National Library of Energy BETA

Sample records for direction uni-directional simulated

  1. Variable mode bi-directional and uni-directional computer communication system

    DOE Patents [OSTI]

    Cornett, Frank N.; Jenkins, Philip N.; Bowman, Terrance L.; Placek, Joseph M.; Thorson, Gregory M.

    2004-12-14

    A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.

  2. Property:Wave Direction | Open Energy Information

    Open Energy Info (EERE)

    Wave Basin + Uni-Directional + Lakefront Tow Tank + Uni-Directional + Los Angeles and Long Beach Harbors Model + Uni-Directional + M MHL 2D WindWave + Uni-Directional + MHL...

  3. Direct Numerical Simulation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Direct Numerical Simulation - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced

  4. Direct Numerical Simulation of Compressible, Turbulent Flow ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The computational mesh for this direct numerical simulation was over 33 billion cells, and was run on up to 102,400 cores under a DoD HPCMP Frontier Project. Nicholas Bisek and ...

  5. Direct numerical simulation of turbulent reacting flows

    SciTech Connect (OSTI)

    Chen, J.H.

    1993-12-01

    The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

  6. Direct Numerical Simulations and Robust Predictions of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name:...

  7. Future Directions in Simulating Solar Geoengineering

    SciTech Connect (OSTI)

    Kravitz, Benjamin S.; Robock, Alan; Boucher, Olivier

    2014-08-05

    Solar geoengineering is a proposed set of technologies to temporarily alleviate some of the consequences of anthropogenic greenhouse gas emissions. The Geoengineering Model Intercomparison Project (GeoMIP) created a framework of geoengineering simulations in climate models that have been performed by modeling centers throughout the world (B. Kravitz et al., The Geoengineering Model Intercomparison Project (GeoMIP), Atmospheric Science Letters, 12(2), 162-167, doi:10.1002/asl.316, 2011). These experiments use state-of-the-art climate models to simulate solar geoengineering via uniform solar reduction, creation of stratospheric sulfate aerosol layers, or injecting sea spray into the marine boundary layer. GeoMIP has been quite successful in its mission of revealing robust features and key uncertainties of the modeled effects of solar geoengineering.

  8. Los Angeles and Long Beach Harbors Model | Open Energy Information

    Open Energy Info (EERE)

    Direction Uni-Directional Simulated Beach Yes Description of Beach Point Fermin to Huntington Beach, CA ChannelTunnelFlume ChannelTunnelFlume None Wind Capabilities Wind...

  9. Direct Numerical Simulations and Robust Predictions of Cloud Cavitation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Collapse | Argonne Leadership Computing Facility cavitating vapor bubbles above a solid wall This image shows cavitating vapor bubbles above a solid wall. The yellow is a visualization of the pressure peak in the center of the bubble cloud. Credit: Computational Science and Engineering Laboratory, ETH Zurich, Switzerland Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name: Petros Koumoutsakos PI Email: petros@ethz.ch Institution: ETH Zürich Allocation

  10. Direct Numerical Simulations and Robust Predictions of Cloud Cavitation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Collapse | Argonne Leadership Computing Facility Initiation of cloud cavitation collapse for 50,000 bubbles Initiation of cloud cavitation collapse for 50,000 bubbles. Jonas Sukys, ETH Zurich Direct Numerical Simulations and Robust Predictions of Cloud Cavitation Collapse PI Name: Petros Koumoutsakos PI Email: petros@ethz.ch Institution: ETH Zurich Allocation Program: INCITE Allocation Hours at ALCF: 72 Million Year: 2016 Research Domain: Engineering Cloud cavitation collapse-the evolution

  11. Direct Numerical Simulations of High Reynolds Number Turbulent Channel Flow

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | Argonne Leadership Computing Facility Visualization of the spanwise vorticity in a turbulent channel. S. Hoyas and O. Flores while they were at Universidad Politecnica de Madrid Direct Numerical Simulations of High Reynolds Number Turbulent Channel Flow PI Name: Robert Moser PI Email: rmoser@ices.utexas.edu Institution: University of Texas Allocation Program: INCITE Allocation Hours at ALCF: 175 Million Year: 2013 Research Domain: Engineering Approximately 28% of U.S. energy resources are

  12. Dynamic simulation of a direct carbonate fuel cell power plant

    SciTech Connect (OSTI)

    Ernest, J.B.; Ghezel-Ayagh, H.; Kush, A.K.

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  13. Direct drive: Simulations and results from the National Ignition Facility

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Radha, P. B.; Hohenberger, M.; Edgell, D. H.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Rosenberg, M. J.; Seka, W.; Shvydky, A.; Boehly, T. R.; et al

    2016-04-19

    Here, the direct-drive implosion physics is being investigated at the National Ignition Facility. The primary goal of the experiments is twofold: to validate modeling related to implosion velocity and to estimate the magnitude of hot-electron preheat. Implosion experiments indicate that the energetics is well-modeled when cross-beam energy transfer (CBET) is included in the simulation and an overall multiplier to the CBET gain factor is employed; time-resolved scattered light and scattered-light spectra display the correct trends. Trajectories from backlit images are well modeled, although those from measured self-emission images indicate increased shell thickness and reduced shell density relative to simulations. Sensitivitymore » analyses indicate that the most likely cause for the density reduction is nonuniformity growth seeded by laser imprint and not laser-energy coupling. Hot-electron preheat is at tolerable levels in the ongoing experiments, although it is expected to increase after the mitigation of CBET. Future work will include continued model validation, imprint measurements, and mitigation of CBET and hot-electron preheat.« less

  14. Stochastic Engine: Direct Incorporation of Measurements Into Predictive Simulations

    SciTech Connect (OSTI)

    Newmark, R L; Aines, R D; Nitao, J J; Hanley, W G; Carle, S; Ramirez, A L; Sengupta, S; Harris, D B

    2001-08-02

    We are creating a new method of combining disparate types of geologic observations and process simulations. Using Bayesian inferencing and an efficient search algorithm, we obtain a consolidated body of knowledge in the form of multiple configurations and parameter values of the system that are consistent with our existing data and process models. In so doing, we effectively estimate the distributions of both individual parameters and system-wide states, and their likelihood of occurrence. This is in contrast with conventional inversion methods, which produce a single deterministic understanding lacking quantitative information about the distribution of uncertainty. We call this combination of probabilistic evaluation and deterministic process simulators the stochastic engine. Our approach allows the investigators to rapidly improve their understanding of system progress, making it particularly valuable for active processes like injection. The Bayesian inferencing is driven by forward process models that predict data values, such as temperature or electrical voltage, for direct comparison to measured field values. We stage the stochastic searches of possible configurations and run the simplest models, such as lithology estimators, at the lower stages. The majority of possible configurations are eliminated from further consideration by the higher stages' more complex models, such as electrical resistance models for geophysical imaging, or flow and transport models for fluid movement. The approach allows for the continuous augmentation of existing data with newly available information to enhance our understanding and reduce the number of high likelihood configurations. This effectively creates a tool capable of dynamically finding models of underground geological systems that are consistent with all available data. The stochastic engine approach will dramatically increase our understanding of large-scale complex systems and the accuracy of predicting their future

  15. Direct Dynamics Simulation of Dissociation of the [CH3--I--OH...

    Office of Scientific and Technical Information (OSTI)

    Ion-Molecule Complex Citation Details In-Document Search Title: Direct Dynamics Simulation of Dissociation of the CH3--I--OH- Ion-Molecule Complex Direct dynamics ...

  16. The Development of A Human Systems Simulation Laboratory: Strategic Direction

    SciTech Connect (OSTI)

    Jacques Hugo; Katya le Blanc; David Gertman

    2012-07-01

    The Human System Simulation Laboratory (HSSL) at the Idaho National Laboratory is one of few facilities of its kind that allows human factors researchers to evaluate various aspects of human performance and human system interaction for proposed reactor designs and upgrades. A basic system architecture, physical configuration and simulation capability were established to enable human factors researchers to support multiple, simultaneous simulations and also different power plant technologies. Although still evolving in terms of its technical and functional architecture, the HSSL is already proving its worth in supporting current and future nuclear industry needs for light water reactor sustainability and small modular reactors. The evolution of the HSSL is focused on continual physical and functional refinement to make it a fully equipped, reconfigurable facility where advanced research, testing and validation studies can be conducted on a wider range of reactor technologies. This requires the implementation of additional plant models to produce empirical research data on human performance with emerging human-system interaction technologies. Additional beneficiaries of this information include system designers and HRA practitioners. To ensure that results of control room crew studies will be generalizable to the existing and evolving fleet of US reactors, future expansion of the HSSL may also include other SMR plant models, plant-specific simulators and a generic plant model aligned to the current generation of pressurized water reactors (PWRs) and future advanced reactor designs. Collaboration with industry partners is also proving to be a vital component of the facility as this helps to establish a formal basis for current and future human performance experiments to support nuclear industry objectives. A long-range Program Plan has been developed for the HSSL to ensure that the facility will support not only the Department of Energys Light Water Reactor

  17. Direct Numerical Simulation of Autoiginition of a Hydrogen Jet in a

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Preheated Cross Flow | Argonne Leadership Computing Facility Numerical Simulation of Autoiginition of a Hydrogen Jet in a Preheated Cross Flow Authors: Abdilghanie, A., Frouzakis, C.E., Fischer, P Autoignition of a nitrogen-diluted hydrogen mixture issuing from a round nozzle into a cross-flowing turbulent stream of preheated air flowing in a channel at a friction Reynolds number Re = 180 is inves- tigated via 3-D direct numerical simulations (DNS) at two crossflow stream temperatures (930

  18. 3D Direct Simulation Monte Carlo Code Which Solves for Geometrics

    Energy Science and Technology Software Center (OSTI)

    1998-01-13

    Pegasus is a 3D Direct Simulation Monte Carlo Code which solves for geometries which can be represented by bodies of revolution. Included are all the surface chemistry enhancements in the 2D code Icarus as well as a real vacuum pump model. The code includes multiple species transport.

  19. Direct numerical simulations of fluid flow, heat transfer and phase changes

    SciTech Connect (OSTI)

    Juric, D.; Tryggvason, G.; Han, J.

    1997-04-01

    Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.

  20. Directions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directions Directions to HAZMAT Challenge LANL's HAZMAT Reesponse Ready Room and Training Facility are ready to welcome this year's Challengers Technical Area 64 - HAZMAT Response...

  1. Direct Simulation of Fully Resolved Vaporizing Droplets in a Turbulent Flow

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | Argonne Leadership Computing Facility Direct Simulation of Fully Resolved Vaporizing Droplets in a Turbulent Flow PI Name: Said Elghobashi PI Email: selghoba@uci.edu Institution: University of California, Irvine Allocation Program: INCITE Allocation Hours at ALCF: 20,000,000 Year: 2012 Research Domain: Engineering This project will enhance the understanding of liquid droplet vaporization and mixing processes in a turbulent flow. All liquid fuel combustion devices, mobile or stationary, use

  2. Direct simulation Monte Carlo investigation of the Richtmyer-Meshkov instability.

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gallis, Michail A.; Koehler, Timothy P.; Torczynski, John R.; Plimpton, Steven J.

    2015-08-14

    The Richtmyer-Meshkov instability (RMI) is investigated using the Direct Simulation Monte Carlo (DSMC) method of molecular gas dynamics. Due to the inherent statistical noise and the significant computational requirements, DSMC is hardly ever applied to hydrodynamic flows. Here, DSMC RMI simulations are performed to quantify the shock-driven growth of a single-mode perturbation on the interface between two atmospheric-pressure monatomic gases prior to re-shocking as a function of the Atwood and Mach numbers. The DSMC results qualitatively reproduce all features of the RMI and are in reasonable quantitative agreement with existing theoretical and empirical models. The DSMC simulations indicate that theremore » is a universal behavior, consistent with previous work in this field that RMI growth follows.« less

  3. Simulation and Experiment on Direct Continuous Casting Process of Lead Frame Copper Alloy

    SciTech Connect (OSTI)

    Huang Guojie; Xie Shuisheng; Cheng Lei [State Key Laboratory for Fabrication and Process of Nonferrous Metals, Beijing General Research Institute for Non-ferrous Metals, 100088 (China)

    2010-06-15

    Direct Continuous Casting (D.C.C) is an important method in casting lead frame copper alloy. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the D.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1413 Kapprox1413 K, the casting speed is between 8 m/happrox10 m/h and the speed of cooling water is between 4.2 m/sapprox4.6 m/s. And the depth of liquid-solid boundary is measured in different casting temperature and casting speed by experiments. The results show the actual measurements have a little deviation with the numerical simulation. The results of numerical simulation provide the significant reference to the actual experiments.

  4. Direct simulation Monte Carlo investigation of the Richtmyer-Meshkov instability.

    SciTech Connect (OSTI)

    Gallis, Michail A.; Koehler, Timothy P.; Torczynski, John R.; Plimpton, Steven J.

    2015-08-14

    The Richtmyer-Meshkov instability (RMI) is investigated using the Direct Simulation Monte Carlo (DSMC) method of molecular gas dynamics. Due to the inherent statistical noise and the significant computational requirements, DSMC is hardly ever applied to hydrodynamic flows. Here, DSMC RMI simulations are performed to quantify the shock-driven growth of a single-mode perturbation on the interface between two atmospheric-pressure monatomic gases prior to re-shocking as a function of the Atwood and Mach numbers. The DSMC results qualitatively reproduce all features of the RMI and are in reasonable quantitative agreement with existing theoretical and empirical models. The DSMC simulations indicate that there is a universal behavior, consistent with previous work in this field that RMI growth follows.

  5. Directions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directions Directions Call Hilton Santa Fe Buffalo Thunder at (505) 455-5555 for shuttle information from the airport and downtown Santa Fe. Driving Directions to Hilton Santa Fe Buffalo Thunder Hilton Santa Fe Buffalo Thunder is located 15 minutes north of Santa Fe. Directions from Albuquerque (bypassing downtown Santa Fe) Take Interstate 25 north towards Santa Fe for approximately 50 miles. From Interstate 25, exit right onto the 599 Northbound Bypass for approximately 14 miles and continue to

  6. Simulation of direct plasma injection for laser ion beam acceleration with a radio frequency quadrupole

    SciTech Connect (OSTI)

    Jin, Q. Y.; Li, Zh. M.; Liu, W.; Zhao, H. Y. Zhang, J. J.; Sha, Sh.; Zhang, Zh. L.; Zhang, X. Zh.; Sun, L. T.; Zhao, H. W.

    2014-07-15

    The direct plasma injection scheme (DPIS) has been being studied at Institute of Modern Physics since several years ago. A C{sup 6+} beam with peak current of 13 mA, energy of 593 keV/u has been successfully achieved after acceleration with DPIS method. To understand the process of DPIS, some simulations have been done as follows. First, with the total current intensity and the relative yields of different charge states for carbon ions measured at the different distance from the target, the absolute current intensities and time-dependences for different charge states are scaled to the exit of the laser ion source in the DPIS. Then with these derived values as the input parameters, the extraction of carbon beam from the laser ion source to the radio frequency quadrupole with DPIS is simulated, which is well agreed with the experiment results.

  7. Direct Monte Carlo simulation of the chemical equilibrium composition of detonation products

    SciTech Connect (OSTI)

    Shaw, M.S.

    1993-06-01

    A new Monte Carlo simulation method has been developed by the author which gives the equilibrium chemical composition of a molecular fluid directly. The usual NPT ensemble (isothermal-isobaric) is implemented with N being the number of atoms instead of molecules. Changes in chemical composition are treated as correlated spatial moves of atoms. Given the interaction potentials between molecular products, ``exact`` EOS points including the equilibrium chemical composition can be determined from the simulations. This method is applied to detonation products at conditions in the region near the Chapman- Jouget state. For the example of NO, it is shown that the CJ detonation velocity can be determined to a few meters per second. A rather small change in cross potentials is shown to shift the chemical equilibrium and the CJ conditions significantly.

  8. Direct numerical simulation of turbulent flow in a rotating square duct

    SciTech Connect (OSTI)

    Dai, Yi-Jun; Huang, Wei-Xi Xu, Chun-Xiao; Cui, Gui-Xiang

    2015-06-15

    A fully developed turbulent flow in a rotating straight square duct is simulated by direct numerical simulations at Re{sub ?} = 300 and 0 ? Ro{sub ?} ? 40. The rotating axis is parallel to two opposite walls of the duct and normal to the main flow. Variations of the turbulence statistics with the rotation rate are presented, and a comparison with the rotating turbulent channel flow is discussed. Rich secondary flow patterns in the cross section are observed by varying the rotation rate. The appearance of a pair of additional vortices above the pressure wall is carefully examined, and the underlying mechanism is explained according to the budget analysis of the mean momentum equations.

  9. Simulation of aerosol direct radiative forcing with RAMS-CMAQ in East Asia

    SciTech Connect (OSTI)

    Han, Xiao; Zhang, Meigen; Han, Zhiewi; Xin, Jin-Yuan; Liu, Xiaohong

    2011-11-14

    The air quality modeling system RAMS-CMAQ is developed to assess aerosol direct radiative forcing by linking simulated meteorological parameters and aerosol mass concentration with the aerosol optical properties/radiative transfer module in this study. The module is capable of accounting for important factors that affect aerosol optical properties and radiative effect, such as incident wave length, aerosol size distribution, water uptake, and internal mixture. Subsequently, the modeling system is applied to simulate the temporal and spatial variations in mass burden, optical properties, and direct radiative forcing of diverse aerosols, including sulfate, nitrate, ammonium, black carbon, organic carbon, dust, and sea salt over East Asia throughout 2005. Model performance is fully evaluated using various observational data, including satellite monitoring of MODIS and surface measurements of EANET (Acid Deposition Monitoring Network), AERONET (Aerosol Robotic Network), and CSHNET (Chinese Sun Hazemeter Network). The correlation coefficients of the comparisons of daily average mass concentrations of sulfate, PM2.5, and PM10 between simulations and EANET measurements are 0.70, 0.61, and 0.64, respectively. It is also determined that the modeled aerosol optical depth (AOD) is in congruence with the observed results from the AERONET, the CSHNET, and the MODIS. The model results suggest that the high AOD values ranging from 0.8 to 1.2 are mainly distributed over the Sichuan Basin as well as over central and southeastern China, in East Asia. The aerosol direct radiative forcing patterns generally followed the AOD patterns. The strongest forcing effect ranging from -12 to -8 W m-2 was mainly distributed over the Sichuan Basin and the eastern China's coastal regions in the all-sky case at TOA, and the forcing effect ranging from -8 to -4 W m-2 could be found over entire eastern China, Korea, Japan, East China Sea, and the sea areas of Japan

  10. Direct Simulation of Turbulent Swept Flow Over a Wire in a Channel |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Argonne Leadership Computing Facility Turbulent Swept Flow Over a Wire in a Channel Authors: RANJAN, R., PANTANO, C., FISCHER, P. Turbulent swept flow over a cylindrical wire placed on a wall of a channel is investigated using direct numerical simulations. This geometry is a model of the flow through the wire-wrapped fuel pins, the heat exchanger, typical of many nuclear reactor designs. Mean flow along and across the wire axis is imposed, leading to the formation of separated flow regions.

  11. Direct Simulation of a Zero-pressure-gradient Turbulent Boundary Layer up

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    to Reθ = 6650 | Argonne Leadership Computing Facility a Zero-pressure-gradient Turbulent Boundary Layer up to Reθ = 6650 Authors: Sillero, J., Jiménez, J., Moser, R.D., Malaya, N.P A direct simulation of an incompressible zero-pressure-gradient turbulent boundary layer over a flat plate is performed in Reθ = 1100-6650 (Reτ ≈ 2025), matching the range of the available numerical channels. The logarithmic region and the separation of scales are clearly observed. Proper turbulent inflow

  12. Electron nanoprobe induced oxidation: A simulation of direct-write purification

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Fowlkes, J. D.; Geier, B.; Lewis, B. B.; Rack, P. D.; Stanford, M. G.; Winkler, R.; Plank, H.

    2015-06-01

    Electron beam direct-write has recently taken a large step forward with the advent of methods to purify deposits. This development has opened the door for future direct-write device prototyping and editing. In one such approach, an additional beam scanning procedure removes carbonaceous impurities via oxidation from metal–carbon deposits (e.g., PtC5) in the presence of H2O or O2 after deposition. So far, critical aspects of the oxidation reaction remain unclear; experiments reveal clearly that electron stimulated oxidation drives the process yet it is not understood why H2O purifies by a bottom-up mechanism while O2 purifies from the top-down. The simulation resultsmore » presented here suggest that the chemisorption of dissolved O2 at buried Pt nanoparticle surfaces controls purification in the top-down case while both the high relative solubility coupled with weak physisorption of H2O explains the bottom-up process. Crucial too is the role that the carbonaceous contaminant itself has on the dissolution and diffusion of O2 and H2O. The results pave the way for simulation driven experiments where (1) the transient densification of the deposit can be accounted for in the initial deposit design stage and (2) the deposition and purification steps can be combined.« less

  13. Electron nanoprobe induced oxidation: A simulation of direct-write purification

    SciTech Connect (OSTI)

    Fowlkes, J. D.; Geier, B.; Lewis, B. B.; Rack, P. D.; Stanford, M. G.; Winkler, R.; Plank, H.

    2015-06-01

    Electron beam direct-write has recently taken a large step forward with the advent of methods to purify deposits. This development has opened the door for future direct-write device prototyping and editing. In one such approach, an additional beam scanning procedure removes carbonaceous impurities via oxidation from metal–carbon deposits (e.g., PtC5) in the presence of H2O or O2 after deposition. So far, critical aspects of the oxidation reaction remain unclear; experiments reveal clearly that electron stimulated oxidation drives the process yet it is not understood why H2O purifies by a bottom-up mechanism while O2 purifies from the top-down. The simulation results presented here suggest that the chemisorption of dissolved O2 at buried Pt nanoparticle surfaces controls purification in the top-down case while both the high relative solubility coupled with weak physisorption of H2O explains the bottom-up process. Crucial too is the role that the carbonaceous contaminant itself has on the dissolution and diffusion of O2 and H2O. The results pave the way for simulation driven experiments where (1) the transient densification of the deposit can be accounted for in the initial deposit design stage and (2) the deposition and purification steps can be combined.

  14. Simulation of an Ar/NH{sub 3} low pressure magnetized direct current discharge

    SciTech Connect (OSTI)

    Li Zhi [School of Science, University of Science and Technology Liaoning, Anshan 114051 (China); School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao Zhen [School of Chemistry and Life Science, Anshan Normal University, Anshan 114007 (China); School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051 (China); Li Xuehui [Physiccal Science and Technical College, Dalian University, Dalian 116622 (China)

    2013-01-15

    A two-dimensional fluid model has been used to investigate the properties of plasma in an Ar/NH{sub 3} low pressure magnetized direct current discharge. We compared the simulation results with the theoretical and experimental results of the other gas discharge in which the magnetic field is considered. Results that obtained using this method are in good agreement with literature. The simulation results show that the positive ammonia ion density follows the positive argon ion density. The Ar{sub 2}{sup +} density is slightly higher than the Ar{sup +} density at 100 mTorr. The largest ammonia ion is NH{sub 3}{sup +} ion, followed by NH{sub 2}{sup +}, NH{sub 4}{sup +}, and NH{sup +} ions. The contribution of NH{sup +} ions to the density of the positive ammonia ions is marginal. The influence of pressure on the plasma discharge has been studied by simulation, and the mechanisms have been discussed. The average plasma density increases as pressure increased. The plasma density appears to be more inhomogeneous than that at the lower pressure. The ratio of charge particles changed as pressure increased. The Ar{sup +} density is slightly higher than the Ar{sub 2}{sup +} density as the pressure increased. It makes NH{sub 4}{sup +} ratio increase as pressure increased. It shows that the electron temperature drops with rising pressure by numerical calculation.

  15. Field simulation of axisymmetric plasma screw pinches by alternating-direction-implicit methods

    SciTech Connect (OSTI)

    Lambert, M.A.

    1996-06-01

    An axisymmetric plasma screw pinch is an axisymmetric column of ionized gaseous plasma radially confined by forces from axial and azimuthal currents driven in the plasma and its surroundings. This dissertation is a contribution to detailed, high resolution computer simulation of dynamic plasma screw pinches in 2-d {ital rz}-coordinates. The simulation algorithm combines electron fluid and particle-in-cell (PIC) ion models to represent the plasma in a hybrid fashion. The plasma is assumed to be quasineutral; along with the Darwin approximation to the Maxwell equations, this implies application of Ampere`s law without displacement current. Electron inertia is assumed negligible so that advective terms in the electron momentum equation are ignored. Electrons and ions have separate scalar temperatures, and a scalar plasma electrical resistivity is assumed. Altemating-direction-implicit (ADI) methods are used to advance the electron fluid drift velocity and the magnetic fields in the simulation. The ADI methods allow time steps larger than allowed by explicit methods. Spatial regions where vacuum field equations have validity are determined by a cutoff density that invokes the quasineutral vacuum Maxwell equations (Darwin approximation). In this dissertation, the algorithm was first checked against ideal MM stability theory, and agreement was nicely demonstrated. However, such agreement is not a new contribution to the research field. Contributions to the research field include new treatments of the fields in vacuum regions of the pinch simulation. The new treatments predict a level of magnetohydrodynamic turbulence near the bulk plasma surface that is higher than predicted by other methods.

  16. Terascale direct numerical simulations of turbulent combustion using S3D

    SciTech Connect (OSTI)

    Chen, Jackie; Klasky, Scott A; Hawkes, Evatt R; Sankaran, Ramanan; Choudhary, Alok; Yoo, Chun S; Liao, Wei-keng; Podhorszki, Norbert

    2009-01-01

    Computational science is paramount to the understanding of underlying processes in internal combustion engines of the future that will utilize non-petroleum-based alternative fuels, including carbon-neutral biofuels, and burn in new combustion regimes that will attain high efficiency while minimizing emissions of particulates and nitrogen oxides. Next-generation engines will likely operate at higher pressures, with greater amounts of dilution and utilize alternative fuels that exhibit a wide range of chemical and physical properties. Therefore, there is a significant role for high-fidelity simulations, direct numerical simulations (DNS), specifically designed to capture key turbulence-chemistry interactions in these relatively uncharted combustion regimes, and in particular, that can discriminate the effects of differences in fuel properties. In DNS, all of the relevant turbulence and flame scales are resolved numerically using high-order accurate numerical algorithms. As a consequence terascale DNS are computationally intensive, require massive amounts of computing power and generate tens of terabytes of data. Recent results from terascale DNS of turbulent flames are presented here, illustrating its role in elucidating flame stabilization mechanisms in a lifted turbulent hydrogen/air jet flame in a hot air coflow, and the flame structure of a fuel-lean turbulent premixed jet flame. Computing at this scale requires close collaborations between computer and combustion scientists to provide optimized scaleable algorithms and software for terascale simulations, efficient collective parallel I/O, tools for volume visualization of multiscale, multivariate data and automating the combustion workflow. The enabling computer science, applied to combustion science, is also required in many other terascale physics and engineering simulations. In particular, performance monitoring is used to identify the performance of key kernels in the DNS code, S3D and especially memory

  17. Direct

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Direct removal of edge-localized pollutant emission in a near-infrared bremsstrahlung measurement J. K. Anderson, a) P. L. Andrew, b) B. E. Chapman, D. Craig, and D. J. Den Hartog Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 ͑Presented on 10 July 2002͒ Visible and near-infrared electron-ion bremsstrahlung measurements in fusion research devices, used to determine the effective ionic charge (Z eff ), are often plagued by pollutant emission

  18. Quasi-spherical direct drive fusion simulations for the Z machine and future accelerators.

    SciTech Connect (OSTI)

    VanDevender, J. Pace; McDaniel, Dillon Heirman; Roderick, Norman Frederick; Nash, Thomas J.

    2007-11-01

    We explored the potential of Quasi-Spherical Direct Drive (QSDD) to reduce the cost and risk of a future fusion driver for Inertial Confinement Fusion (ICF) and to produce megajoule thermonuclear yield on the renovated Z Machine with a pulse shortening Magnetically Insulated Current Amplifier (MICA). Analytic relationships for constant implosion velocity and constant pusher stability have been derived and show that the required current scales as the implosion time. Therefore, a MICA is necessary to drive QSDD capsules with hot-spot ignition on Z. We have optimized the LASNEX parameters for QSDD with realistic walls and mitigated many of the risks. Although the mix-degraded 1D yield is computed to be {approx}30 MJ on Z, unmitigated wall expansion under the > 100 gigabar pressure just before burn prevents ignition in the 2D simulations. A squeezer system of adjacent implosions may mitigate the wall expansion and permit the plasma to burn.

  19. Terascale Direct Numerical Simulations of Turbulent Combustion: Capabilities and Limits (PReSS Talk)

    SciTech Connect (OSTI)

    Yoo, Chun Sang

    2009-03-26

    The rapid growth in computational capabilities has provided great opportunities for direct numerical simulations (DNS) of turbulent combustion, a type of simulations without any turbulence model. With the help of terascale high performance supercomputing (HPC) resources, we are now able to provide fundamental insight into turbulence-chemistry interaction in simple laboratory-scale turbulent flames with detailed chemistry using three-dimensional (3D) DNS. However, the actual domain size of 3D-DNS is still limited within {approx} O(10 cm{sup 3}) due to its tremendously high grid resolution required to resolve the smallest turbulent length scale as well as flame structures. Moreover, 3D-DNS will require more computing powers to investigate next-generation engines, of which operating conditions will be characterized by higher pressures, lower temperatures, and higher levels of dilution. In this talk, I will discuss the capabilities and limits of DNS of turbulent combustion and present some results of ignition/extinction characteristics of a highly diluted hydrogen flame counter-flowing against heated air. The results of our recent 3D-DNS of a spatially-developing turbulent lifted hydrogen jet flame in heated coflow will also be presented. The 3D-DNS was performed at a jet Reynolds number of 11,000 with {approx} 1 billion grid points, which required 3.5 million CPU hours on Cray XT3/XT4 at Oak Ridge National Laboratories.

  20. GPU accelerated flow solver for direct numerical simulation of turbulent flows

    SciTech Connect (OSTI)

    Salvadore, Francesco; Botti, Michela

    2013-02-15

    Graphical processing units (GPUs), characterized by significant computing performance, are nowadays very appealing for the solution of computationally demanding tasks in a wide variety of scientific applications. However, to run on GPUs, existing codes need to be ported and optimized, a procedure which is not yet standardized and may require non trivial efforts, even to high-performance computing specialists. In the present paper we accurately describe the porting to CUDA (Compute Unified Device Architecture) of a finite-difference compressible Navier–Stokes solver, suitable for direct numerical simulation (DNS) of turbulent flows. Porting and validation processes are illustrated in detail, with emphasis on computational strategies and techniques that can be applied to overcome typical bottlenecks arising from the porting of common computational fluid dynamics solvers. We demonstrate that a careful optimization work is crucial to get the highest performance from GPU accelerators. The results show that the overall speedup of one NVIDIA Tesla S2070 GPU is approximately 22 compared with one AMD Opteron 2352 Barcelona chip and 11 compared with one Intel Xeon X5650 Westmere core. The potential of GPU devices in the simulation of unsteady three-dimensional turbulent flows is proved by performing a DNS of a spatially evolving compressible mixing layer.

  1. Direct numerical simulation of shear localization and decomposition reactions in shock-loaded HMX crystal

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Austin, Ryan A.; Barton, Nathan R.; Reaugh, John E.; Fried, Laurence E.

    2015-05-14

    A numerical model is developed to study the shock wave ignition of HMX crystal. The model accounts for the coupling between crystal thermal/mechanical responses and chemical reactions that are driven by the temperature field. This allows for the direct numerical simulation of decomposition reactions in the hot spots formed by shock/impact loading. The model is used to simulate intragranular pore collapse under shock wave loading. In a reference case: (i) shear-enabled micro-jetting is responsible for a modest extent of reaction in the pore collapse region, and (ii) shear banding is found to be an important mode of localization. The shearmore » bands, which are filled with molten HMX, grow out of the pore collapse region and serve as potential ignition sites. The model predictions of shear banding and reactivity are found to be quite sensitive to the respective flow strengths of the solid and liquid phases. In this regard, it is shown that reasonable assumptions of liquid-HMX viscosity can lead to chemical reactions within the shear bands on a nanosecond time scale.« less

  2. A review of direct numerical simulations of astrophysical detonations and their implications

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Parete-Koon, Suzanne T.; Smith, Christopher R.; Papatheodore, Thomas L.; Bronson Messer, O. E.

    2013-04-11

    Multi-dimensional direct numerical simulations (DNS) of astrophysical detonations in degenerate matter have revealed that the nuclear burning is typically characterized by cellular structure caused by transverse instabilities in the detonation front. Type Ia supernova modelers often use one- dimensional DNS of detonations as inputs or constraints for their whole star simulations. While these one-dimensional studies are useful tools, the true nature of the detonation is multi-dimensional. The multi-dimensional structure of the burning influences the speed, stability, and the composition of the detonation and its burning products, and therefore, could have an impact on the spectra of Type Ia supernovae. Considerablemore » effort has been expended modeling Type Ia supernovae at densities above 1x107 g∙cm-3 where the complexities of turbulent burning dominate the flame propagation. However, most full star models turn the nuclear burning schemes off when the density falls below 1x107 g∙cm-3 and distributed burning begins. The deflagration to detonation transition (DDT) is believed to occur at just these densities and consequently they are the densities important for studying the properties of the subsequent detonation. In conclusion, this work reviews the status of DNS studies of detonations and their possible implications for Type Ia supernova models. It will cover the development of Detonation theory from the first simple Chapman-Jouguet (CJ) detonation models to the current models based on the time-dependent, compressible, reactive flow Euler equations of fluid dynamics.« less

  3. Direct numerical simulation of shear localization and decomposition reactions in shock-loaded HMX crystal

    SciTech Connect (OSTI)

    Austin, Ryan A.; Barton, Nathan R.; Reaugh, John E.; Fried, Laurence E.

    2015-05-14

    A numerical model is developed to study the shock wave ignition of HMX crystal. The model accounts for the coupling between crystal thermal/mechanical responses and chemical reactions that are driven by the temperature field. This allows for the direct numerical simulation of decomposition reactions in the hot spots formed by shock/impact loading. The model is used to simulate intragranular pore collapse under shock wave loading. In a reference case: (i) shear-enabled micro-jetting is responsible for a modest extent of reaction in the pore collapse region, and (ii) shear banding is found to be an important mode of localization. The shear bands, which are filled with molten HMX, grow out of the pore collapse region and serve as potential ignition sites. The model predictions of shear banding and reactivity are found to be quite sensitive to the respective flow strengths of the solid and liquid phases. In this regard, it is shown that reasonable assumptions of liquid-HMX viscosity can lead to chemical reactions within the shear bands on a nanosecond time scale.

  4. Directed nanoscale self-assembly of molecular wires interconnecting nodal points using Monte Carlo simulations

    SciTech Connect (OSTI)

    Boscoboinik, A. M.; Manzi, S. J.; Tysoe, W. T.; Pereyra, V. D.; Boscoboinik, J. A.

    2015-09-10

    The influence of directing agents in the self-assembly of molecular wires to produce two-dimensional electronic nanoarchitectures is studied here using a Monte Carlo approach to simulate the effect of arbitrarily locating nodal points on a surface, from which the growth of self-assembled molecular wires can be nucleated. This is compared to experimental results reported for the self-assembly of molecular wires when 1,4-phenylenediisocyanide (PDI) is adsorbed on Au(111). The latter results in the formation of (Au-PDI)n organometallic chains, which were shown to be conductive when linked between gold nanoparticles on an insulating substrate. The present study analyzes, by means of stochastic methods, the influence of variables that affect the growth and design of self-assembled conductive nanoarchitectures, such as the distance between nodes, coverage of the monomeric units that leads to the formation of the desired architectures, and the interaction between the monomeric units. As a result, this study proposes an approach and sets the stage for the production of complex 2D nanoarchitectures using a bottom-up strategy but including the use of current state-of-the-art top-down technology as an integral part of the self-assembly strategy.

  5. Directed nanoscale self-assembly of molecular wires interconnecting nodal points using Monte Carlo simulations

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Boscoboinik, A. M.; Manzi, S. J.; Tysoe, W. T.; Pereyra, V. D.; Boscoboinik, J. A.

    2015-09-10

    The influence of directing agents in the self-assembly of molecular wires to produce two-dimensional electronic nanoarchitectures is studied here using a Monte Carlo approach to simulate the effect of arbitrarily locating nodal points on a surface, from which the growth of self-assembled molecular wires can be nucleated. This is compared to experimental results reported for the self-assembly of molecular wires when 1,4-phenylenediisocyanide (PDI) is adsorbed on Au(111). The latter results in the formation of (Au-PDI)n organometallic chains, which were shown to be conductive when linked between gold nanoparticles on an insulating substrate. The present study analyzes, by means of stochasticmore » methods, the influence of variables that affect the growth and design of self-assembled conductive nanoarchitectures, such as the distance between nodes, coverage of the monomeric units that leads to the formation of the desired architectures, and the interaction between the monomeric units. As a result, this study proposes an approach and sets the stage for the production of complex 2D nanoarchitectures using a bottom-up strategy but including the use of current state-of-the-art top-down technology as an integral part of the self-assembly strategy.« less

  6. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to amore » constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.« less

  7. Direct Numerical Simulations of Autoignition in Stratified Dimethyl-ether (DME)/Air Turbulent Mixtures

    SciTech Connect (OSTI)

    Bansal, Gaurav; Mascarenhas, Ajith; Chen, Jacqueline H.

    2014-10-01

    In our paper, two- and three-dimensional direct numerical simulations (DNS) of autoignition phenomena in stratified dimethyl-ether (DME)/air turbulent mixtures are performed. A reduced DME oxidation mechanism, which was obtained using rigorous mathematical reduction and stiffness removal procedure from a detailed DME mechanism with 55 species, is used in the present DNS. The reduced DME mechanism consists of 30 chemical species. This study investigates the fundamental aspects of turbulence-mixing-autoignition interaction occurring in homogeneous charge compression ignition (HCCI) engine environments. A homogeneous isotropic turbulence spectrum is used to initialize the velocity field in the domain. Moreover, the computational configuration corresponds to a constant volume combustion vessel with inert mass source terms added to the governing equations to mimic the pressure rise due to piston motion, as present in practical engines. DME autoignition is found to be a complex three-staged process; each stage corresponds to a distinct chemical kinetic pathway. The distinct role of turbulence and reaction in generating scalar gradients and hence promoting molecular transport processes are investigated. Then, by applying numerical diagnostic techniques, the different heat release modes present in the igniting mixture are identified. In particular, the contribution of homogeneous autoignition, spontaneous ignition front propagation, and premixed deflagration towards the total heat release are quantified.

  8. Direct Vlasov simulations of electron-attracting cylindrical Langmuir probes in flowing plasmas

    SciTech Connect (OSTI)

    Snchez-Arriaga, G.; Pastor-Moreno, D.

    2014-07-15

    Current collection by positively polarized cylindrical Langmuir probes immersed in flowing plasmas is analyzed using a non-stationary direct Vlasov-Poisson code. A detailed description of plasma density spatial structure as a function of the probe-to-plasma relative velocity U is presented. Within the considered parametric domain, the well-known electron density maximum close to the probe is weakly affected by U. However, in the probe wake side, the electron density minimum becomes deeper as U increases and a rarified plasma region appears. Sheath radius is larger at the wake than at the front side. Electron and ion distribution functions show specific features that are the signature of probe motion. In particular, the ion distribution function at the probe front side exhibits a filament with positive radial velocity. It corresponds to a population of rammed ions that were reflected by the electric field close to the positively biased probe. Numerical simulations reveal that two populations of trapped electrons exist: one orbiting around the probe and the other with trajectories confined at the probe front side. The latter helps to neutralize the reflected ions, thus explaining a paradox in past probe theory.

  9. Test particle simulation of direct laser acceleration in a density-modulated plasma waveguide

    SciTech Connect (OSTI)

    Lin, M.-W.; Jovanovic, I.

    2012-11-15

    Direct laser acceleration (DLA) of electrons by the use of the intense axial electric field of an ultrafast radially polarized laser pulse is a promising technique for future compact accelerators. Density-modulated plasma waveguides can be implemented for guiding the propagation of the laser pulse to extend the acceleration distance and for the quasi-phase-matching between the accelerated electrons and the laser pulse. A test particle model is developed to study the optimal axial density modulation structure of plasma waveguides for laser pulses to efficiently accelerate co-propagating electrons. A simple analytical approach is also presented, which can be used to estimate the energy gain in DLA. The analytical model is validated by the test particle simulation. The effect of injection phase and acceleration of electrons injected at various radial positions are studied. The results indicate that a positively chirped density modulation of the waveguide structure is required to accelerate electron with low initial energies, and can be effectively optimized. A wider tolerance on the injection phase and radial distance from the waveguide axis exists for electrons injected with a higher initial energy.

  10. SIMULATION AND MOCKUP OF SNS JET-FLOW TARGET WITH WALL JET FOR CAVITATION DAMAGE MITIGATION

    SciTech Connect (OSTI)

    Wendel, Mark W; Geoghegan, Patrick J; Felde, David K

    2014-01-01

    Pressure waves created in liquid mercury pulsed spallation targets at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory induce cavitation damage on the stainless steel target container. The cavitation damage is thought to limit the lifetime of the target for power levels at and above 1 MW. Severe through-wall cavitation damage on an internal wall near the beam entrance window has been observed in spent-targets. Surprisingly though, there is very little damage on the walls that bound an annular mercury channel that wraps around the front and outside of the target. The mercury flow through this channel is characterized by smooth, attached streamlines. One theory to explain this lack of damage is that the uni-directional flow biases the direction of the collapsing cavitation bubble, reducing the impact pressure and subsequent damage. The theory has been reinforced by in-beam separate effects data. For this reason, a second-generation SNS mercury target has been designed with an internal wall jet configuration intended to protect the concave wall where damage has been observed. The wall jet mimics the annular flow channel streamlines, but since the jet is bounded on only one side, the momentum is gradually diffused by the bulk flow interactions as it progresses around the cicular path of the target nose. Numerical simulations of the flow through this jet-flow target have been completed, and a water loop has been assembled with a transparent test target in order to visualize and measure the flow field. This paper presents the wall jet simulation results, as well as early experimental data from the test loop.

  11. Stimulated Raman signals at conical intersections: Ab initio surface hopping simulation protocol with direct propagation of the nuclear wave function

    SciTech Connect (OSTI)

    Kowalewski, Markus Mukamel, Shaul

    2015-07-28

    Femtosecond Stimulated Raman Spectroscopy (FSRS) signals that monitor the excited state conical intersections dynamics of acrolein are simulated. An effective time dependent Hamiltonian for two C—H vibrational marker bands is constructed on the fly using a local mode expansion combined with a semi-classical surface hopping simulation protocol. The signals are obtained by a direct forward and backward propagation of the vibrational wave function on a numerical grid. Earlier work is extended to fully incorporate the anharmonicities and intermode couplings.

  12. Osborne Reynolds pipe flow: Direct simulation from laminar through gradual transition to fully developed turbulence

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Xiaohua; Moin, Parviz; Adrian, Ronald J.; Baltzer, Jon R.

    2015-06-15

    We report that the precise dynamics of breakdown in pipe transition is a century-old unresolved problem in fluid mechanics. We demonstrate that the abruptness and mysteriousness attributed to the Osborne Reynolds pipe transition can be partially resolved with a spatially developing direct simulation that carries weakly but finitely perturbed laminar inflow through gradual rather than abrupt transition arriving at the fully developed turbulent state. Our results with this approach show during transition the energy norms of such inlet perturbations grow exponentially rather than algebraically with axial distance. When inlet disturbance is located in the core region, helical vortex filaments evolvemore » into large-scale reverse hairpin vortices. The interaction of these reverse hairpins among themselves or with the near-wall flow when they descend to the surface from the core produces small-scale hairpin packets, which leads to breakdown. When inlet disturbance is near the wall, certain quasi-spanwise structure is stretched into a Lambda vortex, and develops into a large-scale hairpin vortex. Small-scale hairpin packets emerge near the tip region of the large-scale hairpin vortex, and subsequently grow into a turbulent spot, which is itself a local concentration of small-scale hairpin vortices. This vortex dynamics is broadly analogous to that in the boundary layer bypass transition and in the secondary instability and breakdown stage of natural transition, suggesting the possibility of a partial unification. Under parabolic base flow the friction factor overshoots Moody’s correlation. Plug base flow requires stronger inlet disturbance for transition. Finally, accuracy of the results is demonstrated by comparing with analytical solutions before breakdown, and with fully developed turbulence measurements after the completion of transition.« less

  13. CASL-8-2015-0103-000 Multi-Phase Flow: Direct Numerical Simulation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Notre Dame July 8-10, 2013 CASL-U-2015-0103-000 Multi-Phase Flow: Direct ... Laboratories, July 9-10, 2013 CASL-U-2015-0103-000 Multi-Phase Flow: Direct ...

  14. Direct comparisons of X-ray scattering and atomistic molecular dynamics simulations for precise acid copolymers and ionomers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buitrago, C. Francisco; Bolintineanu, Dan; Seitz, Michelle E.; Opper, Kathleen L.; Wagener, Kenneth B.; Stevens, Mark J.; Frischknecht, Amalie Lucile; Winey, Karen I.

    2015-02-09

    Designing acid- and ion-containing polymers for optimal proton, ion, or water transport would benefit profoundly from predictive models or theories that relate polymer structures with ionomer morphologies. Recently, atomistic molecular dynamics (MD) simulations were performed to study the morphologies of precise poly(ethylene-co-acrylic acid) copolymer and ionomer melts. Here, we present the first direct comparisons between scattering profiles, I(q), calculated from these atomistic MD simulations and experimental X-ray data for 11 materials. This set of precise polymers has spacers of exactly 9, 15, or 21 carbons between acid groups and has been partially neutralized with Li, Na, Cs, or Zn. Inmore » these polymers, the simulations at 120 °C reveal ionic aggregates with a range of morphologies, from compact, isolated aggregates (type 1) to branched, stringy aggregates (type 2) to branched, stringy aggregates that percolate through the simulation box (type 3). Excellent agreement is found between the simulated and experimental scattering peak positions across all polymer types and aggregate morphologies. The shape of the amorphous halo in the simulated I(q) profile is in excellent agreement with experimental I(q). We found that the modified hard-sphere scattering model fits both the simulation and experimental I(q) data for type 1 aggregate morphologies, and the aggregate sizes and separations are in agreement. Given the stringy structure in types 2 and 3, we develop a scattering model based on cylindrical aggregates. Both the spherical and cylindrical scattering models fit I(q) data from the polymers with type 2 and 3 aggregates equally well, and the extracted aggregate radii and inter- and intra-aggregate spacings are in agreement between simulation and experiment. Furthermore, these dimensions are consistent with real-space analyses of the atomistic MD simulations. By combining simulations and experiments, the ionomer scattering peak can be associated with the

  15. Direct Numerical Simulation of Pore-Scale Flow in a Bead Pack: Comparison with Magnetic Resonance Imaging Observations

    SciTech Connect (OSTI)

    Yang, Xiaofan; Scheibe, Timothy D.; Richmond, Marshall C.; Perkins, William A.; Vogt, Sarah J.; Codd, Sarah L.; Seymour, Joseph D.; Mckinley, Matthew I.

    2013-04-01

    A significant body of current research is aimed at developing methods for numerical simulation of flow and transport in porous media that explicitly resolve complex pore and solid geometries, and at utilizing such models to study the relationships between fundamental pore-scale processes and macroscopic manifestations at larger (i.e., Darcy) scales. A number of different numerical methods for pore-scale simulation have been developed, and have been extensively tested and validated for simplified geometries. However, validation of pore-scale simulations of fluid velocity for complex, three-dimensional (3D) pore geometries that are representative of natural porous media is challenging due to our limited ability to measure pore-scale velocity in such systems. Recent advances in magnetic resonance imaging (MRI) offer the opportunity to measure not only the pore geometry, but also local fluid velocities under steady-state flow conditions in 3D and with high spatial resolution. In this paper, we present a 3D velocity field measured at sub-pore resolution (tens of micrometers) over a centimeter-scale 3D domain using MRI methods. We have utilized the measured pore geometry to perform 3D simulations of Navier-Stokes flow over the same domain using direct numerical simulation techniques. We present a comparison of the numerical simulation results with the measured velocity field. It is shown that the numerical results match the observed velocity patterns well overall except for a variance and small systematic scaling which can be attributed to the known experimental error in the MRI measurements. The comparisons presented here provide strong validation of the pore-scale simulation methods and new insights for interpretation of uncertainty in MRI measurements of pore-scale velocity. This study also provides a potential benchmark for future comparison of other pore-scale simulation methods.

  16. Towards Direct Simulation of Future Tropical Cyclone Statistics in a High-Resolution Global Atmospheric Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wehner, Michael F.; Bala, G.; Duffy, Phillip; Mirin, Arthur A.; Romano, Raquel

    2010-01-01

    We present a set of high-resolution global atmospheric general circulation model (AGCM) simulations focusing on the model's ability to represent tropical storms and their statistics. We find that the model produces storms of hurricane strength with realistic dynamical features. We also find that tropical storm statistics are reasonable, both globally and in the north Atlantic, when compared to recent observations. The sensitivity of simulated tropical storm statistics to increases in sea surface temperature (SST) is also investigated, revealing that a credible late 21st century SST increase produced increases in simulated tropical storm numbers and intensities in all ocean basins. Whilemore » this paper supports previous high-resolution model and theoretical findings that the frequency of very intense storms will increase in a warmer climate, it differs notably from previous medium and high-resolution model studies that show a global reduction in total tropical storm frequency. However, we are quick to point out that this particular model finding remains speculative due to a lack of radiative forcing changes in our time-slice experiments as well as a focus on the Northern hemisphere tropical storm seasons.« less

  17. DIRECT NUMERICAL SIMULATIONS OF REFLECTION-DRIVEN, REDUCED MAGNETOHYDRODYNAMIC TURBULENCE FROM THE SUN TO THE ALFVN CRITICAL POINT

    SciTech Connect (OSTI)

    Perez, Jean Carlos; Chandran, Benjamin D. G.

    2013-10-20

    We present direct numerical simulations of inhomogeneous reduced magnetohydrodynamic (RMHD) turbulence between the Sun and the Alfvn critical point. These are the first such simulations that take into account the solar-wind outflow velocity and the radial inhomogeneity of the background solar wind without approximating the nonlinear terms in the governing equations. RMHD turbulence is driven by outward-propagating Alfvn waves (z {sup +} fluctuations) launched from the Sun, which undergo partial non-WKB reflection to produce sunward-propagating Alfvn waves (z {sup } fluctuations). We present 10 simulations with different values of the correlation time ?{sub c{sub sun}{sup +}} and perpendicular correlation length L{sub ?} of outward-propagating Alfvn waves at the coronal base. We find that between 15% and 33% of the z {sup +} energy launched into the corona dissipates between the coronal base and Alfvn critical point. Between 33% and 40% of this input energy goes into work on the solar-wind outflow, and between 22% and 36% escapes as z {sup +} fluctuations through the simulation boundary at r = r{sub A}. The z {sup } power spectra scale like k{sub perpendicular}{sup -?{sup }}, where k is the wavenumber in the plane perpendicular to B{sub 0}. In our simulation with the smallest value of ?{sub c{sub sun}{sup +}} (?2 minutes) and largest value of L{sub ?} (2 10{sup 4} km), we find that ?{sup +} decreases approximately linearly with increasing ln (r), reaching a value of 1.3 at r = 11.1 R{sub ?}. Our simulations with larger values of ?{sub c{sub sun}{sup +}} exhibit alignment between the contours of constant ?{sup +}, ?{sup }, ?{sub 0}{sup +}, and ?{sub 0}{sup -}, where ?{sup } are the Elssser potentials and ?{sub 0}{sup } are the outer-scale parallel Elssser vorticities.

  18. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations

    SciTech Connect (OSTI)

    Baumgaertel, J. A.; Bradley, P. A.; Hsu, S. C.; Cobble, J. A.; Hakel, P.; Tregillis, I. L.; Krasheninnikova, N. S.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Obrey, K. D.; Batha, S.; Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T.

    2014-05-15

    Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

  19. Study of Particle Rotation Effect in Gas-Solid Flows using Direct Numerical Simulation with a Lattice Boltzmann Method

    SciTech Connect (OSTI)

    Kwon, Kyung; Fan, Liang-Shih; Zhou, Qiang; Yang, Hui

    2014-09-30

    A new and efficient direct numerical method with second-order convergence accuracy was developed for fully resolved simulations of incompressible viscous flows laden with rigid particles. The method combines the state-of-the-art immersed boundary method (IBM), the multi-direct forcing method, and the lattice Boltzmann method (LBM). First, the multi-direct forcing method is adopted in the improved IBM to better approximate the no-slip/no-penetration (ns/np) condition on the surface of particles. Second, a slight retraction of the Lagrangian grid from the surface towards the interior of particles with a fraction of the Eulerian grid spacing helps increase the convergence accuracy of the method. An over-relaxation technique in the procedure of multi-direct forcing method and the classical fourth order Runge-Kutta scheme in the coupled fluid-particle interaction were applied. The use of the classical fourth order Runge-Kutta scheme helps the overall IB-LBM achieve the second order accuracy and provides more accurate predictions of the translational and rotational motion of particles. The preexistent code with the first-order convergence rate is updated so that the updated new code can resolve the translational and rotational motion of particles with the second-order convergence rate. The updated code has been validated with several benchmark applications. The efficiency of IBM and thus the efficiency of IB-LBM were improved by reducing the number of the Lagragian markers on particles by using a new formula for the number of Lagrangian markers on particle surfaces. The immersed boundary-lattice Boltzmann method (IBLBM) has been shown to predict correctly the angular velocity of a particle. Prior to examining drag force exerted on a cluster of particles, the updated IB-LBM code along with the new formula for the number of Lagrangian markers has been further validated by solving several theoretical problems. Moreover, the unsteadiness of the drag force is examined when a

  20. Direct Numerical Simulation of Interfacial Flows: Implicit Sharp-Interface Method (I-SIM)

    SciTech Connect (OSTI)

    Robert Nourgaliev; Theo Theofanous; HyeongKae Park; Vincent Mousseau; Dana Knoll

    2008-01-01

    In recent work (Nourgaliev, Liou, Theofanous, JCP in press) we demonstrated that numerical simulations of interfacial flows in the presence of strong shear must be cast in dynamically sharp terms (sharp interface treatment or SIM), and that moreover they must meet stringent resolution requirements (i.e., resolving the critical layer). The present work is an outgrowth of that work aiming to overcome consequent limitations on the temporal treatment, which become still more severe in the presence of phase change. The key is to avoid operator splitting between interface motion, fluid convection, viscous/heat diffusion and reactions; instead treating all these non-linear operators fully-coupled within a Newton iteration scheme. To this end, the SIMs cut-cell meshing is combined with the high-orderaccurate implicit Runge-Kutta and the recovery Discontinuous Galerkin methods along with a Jacobian-free, Krylov subspace iteration algorithm and its physics-based preconditioning. In particular, the interfacial geometry (i.e., markers positions and volumes of cut cells) is a part of the Newton-Krylov solution vector, so that the interface dynamics and fluid motions are fully-(non-linearly)-coupled. We show that our method is: (a) robust (L-stable) and efficient, allowing to step over stability time steps at will while maintaining high-(up to the 5th)-order temporal accuracy; (b) fully conservative, even near multimaterial contacts, without any adverse consequences (pressure/velocity oscillations); and (c) highorder-accurate in spatial discretization (demonstrated here up to the 12th-order for smoothin-the-bulk-fluid flows), capturing interfacial jumps sharply, within one cell. Performance is illustrated with a variety of test problems, including low-Mach-number manufactured solutions, shock dynamics/tracking with slow dynamic time scales, and multi-fluid, highspeed shock-tube problems. We briefly discuss preconditioning, and we introduce two physics-based preconditioners

  1. A Tow-Level Progressive Damage for Simulating Carbon-Fiber Textile Composites: Interim Report

    SciTech Connect (OSTI)

    Zywicz, E.

    2000-07-01

    A numerical approach to model the elasto-plastic and tensile damage response of tri-axially braided carbon-fiber polymeric-matrix composites is developed. It is micromechanically based and consists of a simplified unit cell geometry, a plane-stress tow-level constitutive relationship, a one-dimensional undulation constitutive law, and a non-traditional shell element integration rule. The braided composite lamina is idealized as periodic in the plane, and a simplified three-layer representative volume (RV) is assembled from axial and braider tows and pure resin regions. The constituents in each layer are homogenized with an iso-strain assumption in the fiber-direction and an iso-stress condition in the other directions. In the upper and lower layers, the fiber-direction strain is additively decomposed into an undulation and a tow portion. A finite-deformation tow model predicts the plane-stress tow response and is coupled to the undulation constitutive relationship. The overall braid model is implemented in DYNA3D and works with traditional shell elements. The finite-deformation tow constitutive relationship is derived from the fiber elasticity and the isotropic elasto-plastic power-law hardening matrix response using a thermodynamic framework and simple homogenization assumptions. The model replicates tensile damage evolution, in a smeared sense, parallel and perpendicular to the fiber axis and is regularized to yield mesh independent results. The tow-level model demonstrates reasonable agreement, prior to damage, with detailed three-dimensional FE (finite element) elasto-plastic simulations of aligned, periodically arranged, uni-directional composites. The 3-layer braid model response is compared with predictions obtained from detailed micromechanical simulations of the braid's unit cell in uni-axial extension, shear, and flexure for three braid angles. The elastic properties show good agreement as does the non-linear response for loadings dominated by the axial

  2. Direct first-principles simulation of a high-performance electron emitter: Lithium-oxide-coated diamond surface

    SciTech Connect (OSTI)

    Miyamoto, Yoshiyuki Miyazaki, Takehide; Takeuchi, Daisuke; Yamasaki, Satoshi

    2014-09-28

    We examined the field emission properties of lithium(Li)/oxygen(O)-co-terminated diamond (001) surface [C(001)-LiO] through real-time electron dynamics simulation under an applied field. The current emitted from this surface was found to be more than four-fold that emitted by an H-terminated (001) surface, the latter being a typical negative electron affinity system. This high performance is attributed to the Li layer, which bends the potential wall of O-induced electron pockets down in the direction of vacuum, thus facilitating electron emission. Detailed analysis of the emitted electrons and the profile of the self-consistent potential elucidated that the role of O atoms changes from an electron barrier on OH-terminated diamond surfaces to an outlet for electron emission on C(001)-LiO.

  3. MEAN-FIELD MODELING OF AN α{sup 2} DYNAMO COUPLED WITH DIRECT NUMERICAL SIMULATIONS OF RIGIDLY ROTATING CONVECTION

    SciTech Connect (OSTI)

    Masada, Youhei; Sano, Takayoshi E-mail: sano@ile.osaka-u.ac.jp

    2014-10-10

    The mechanism of large-scale dynamos in rigidly rotating stratified convection is explored by direct numerical simulations (DNS) in Cartesian geometry. A mean-field dynamo model is also constructed using turbulent velocity profiles consistently extracted from the corresponding DNS results. By quantitative comparison between the DNS and our mean-field model, it is demonstrated that the oscillatory α{sup 2} dynamo wave, excited and sustained in the convection zone, is responsible for large-scale magnetic activities such as cyclic polarity reversal and spatiotemporal migration. The results provide strong evidence that a nonuniformity of the α-effect, which is a natural outcome of rotating stratified convection, can be an important prerequisite for large-scale stellar dynamos, even without the Ω-effect.

  4. Direct Numerical Simulation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing ... Heavy Duty Fuels DISI Combustion HCCISCCI Fundamentals Spray Combustion Modeling ...

  5. Analysis of turbulent transport and mixing in transitional Rayleigh/Taylor unstable flow using direct numerical simulation data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

    Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipationmoreand destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic

  6. A method for the direct numerical simulation of hypersonic boundary-layer instability with finite-rate chemistry

    SciTech Connect (OSTI)

    Marxen, Olaf, E-mail: olaf.marxen@vki.ac.be [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States) [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States); Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium); Magin, Thierry E. [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium)] [Aeronautics and Aerospace Department, von Karman Institute for Fluid Dynamics, Chausse de Waterloo, 72, 1640 Rhode-St-Gense (Belgium); Shaqfeh, Eric S.G.; Iaccarino, Gianluca [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)] [Center for Turbulence Research, Building 500, Stanford University, Stanford, CA 94305-3035 (United States)

    2013-12-15

    A new numerical method is presented here that allows to consider chemically reacting gases during the direct numerical simulation of a hypersonic fluid flow. The method comprises the direct coupling of a solver for the fluid mechanical model and a library providing the physio-chemical model. The numerical method for the fluid mechanical model integrates the compressible NavierStokes equations using an explicit time advancement scheme and high-order finite differences. This NavierStokes code can be applied to the investigation of laminar-turbulent transition and boundary-layer instability. The numerical method for the physio-chemical model provides thermodynamic and transport properties for different gases as well as chemical production rates, while here we exclusively consider a five species air mixture. The new method is verified for a number of test cases at Mach 10, including the one-dimensional high-temperature flow downstream of a normal shock, a hypersonic chemical reacting boundary layer in local thermodynamic equilibrium and a hypersonic reacting boundary layer with finite-rate chemistry. We are able to confirm that the diffusion flux plays an important role for a high-temperature boundary layer in local thermodynamic equilibrium. Moreover, we demonstrate that the flow for a case previously considered as a benchmark for the investigation of non-equilibrium chemistry can be regarded as frozen. Finally, the new method is applied to investigate the effect of finite-rate chemistry on boundary layer instability by considering the downstream evolution of a small-amplitude wave and comparing results with those obtained for a frozen gas as well as a gas in local thermodynamic equilibrium.

  7. Evidence for Bolgiano-Obukhov scaling in rotating stratified turbulence using high-resolution direct numerical simulations

    SciTech Connect (OSTI)

    Rosenberg, Duane L; Pouquet, Dr. Annick; Mininni, Dr. Pablo D.; Marino, Dr. Raffaele

    2015-01-01

    We report results on rotating stratified turbulence in the absence of forcing, with large-scale isotropic initial conditions, using direct numerical simulations computed on grids of up to $4096^3$ points. The Reynolds and Froude numbers are respectively equal to $Re=5.4\\times 10^4$ and $Fr=0.0242$. The ratio of the Brunt-V\\"ais\\"al\\"a to the inertial wave frequency, $N/f$, is taken to be equal to 5, a choice appropriate to model the dynamics of the southern abyssal ocean at mid latitudes. This gives a global buoyancy Reynolds number $R_B=ReFr^2=32$, a value sufficient for some isotropy to be recovered in the small scales beyond the Ozmidov scale, but still moderate enough that the intermediate scales where waves are prevalent are well resolved. We concentrate on the large-scale dynamics and confirm that the Froude number based on a typical vertical length scale is of order unity, with strong gradients in the vertical. Two characteristic scales emerge from this computation, and are identified from sharp variations in the spectral distribution of either total energy or helicity. A spectral break is also observed at a scale at which the partition of energy between the kinetic and potential modes changes abruptly, and beyond which a Kolmogorov-like spectrum recovers. Large slanted layers are ubiquitous in the flow in the velocity and temperature fields, and a large-scale enhancement of energy is also observed, directly attributable to the effect of rotation.

  8. A direct numerical simulation-based investigation and modeling of pressure Hessian effects on compressible velocity gradient dynamics

    SciTech Connect (OSTI)

    Danish, Mohammad Suman, Sawan Srinivasan, Balaji

    2014-12-15

    The pressure Hessian tensor plays a key role in shaping the behavior of the velocity gradient tensor, and in turn, that of many incumbent non-linear processes in a turbulent flow field. In compressible flows, the role of pressure Hessian is even more important because it represents the level of fluid-thermodynamic coupling existing in the flow field. In this work, we first perform a direct numerical simulation-based study to clearly identify, isolate, and understand various important inviscid mechanisms that govern the evolution of the pressure Hessian tensor in compressible turbulence. The ensuing understanding is then employed to introduce major improvements to the existing Lagrangian model of the pressure Hessian tensor (the enhanced Homogenized Euler equation or EHEE) in terms of (i) non-symmetric, non-isentropic effects and (ii) improved representation of the anisotropic portion of the pressure Hessian tensor. Finally, we evaluate the new model extensively by comparing the new model results against known turbulence behavior over a range of Reynolds and Mach numbers. Indeed, the new model shows much improved performance as compared to the EHEE model.

  9. Analysis of turbulent transport and mixing in transitional Rayleigh–Taylor unstable flow using direct numerical simulation data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schilling, Oleg; Mueschke, Nicholas J.

    2010-10-18

    Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipationmore » and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic

  10. Comparison of direct numerical simulation of lean premixed methane-air flames with strained laminar flame calculations.

    SciTech Connect (OSTI)

    Chen, Jacqueline H.; Hawkes, Evatt R.

    2004-08-01

    Direct numerical simulation (DNS) with complex chemistry was used to study statistics of displacement and consumption speeds in turbulent lean premixed methane-air flames. The main focus of the study is an evaluation of the extent to which a turbulent flame in the thin reaction zones regime can be described by an ensemble of strained laminar flames. Conditional averages with respect to strain for displacement and consumption speeds are presented over a wide range of strain typically encountered in a turbulent flame, compared with previous studies that either made local pointwise comparisons or conditioned the data on small strain and curvature. The conditional averages for positive strains are compared with calculated data from two different canonical strained laminar configurations to determine which is the optimal representation of a laminar flame structure embedded in a turbulent flame: the reactant-to-product (R-to-P) configuration or the symmetric twin flame configuration. Displacement speed statistics are compared for the progress-variable isosurface of maximum reaction rate and an isosurface toward the fresh gases, which are relevant for both modeling and interpretation of experiment results. Displacement speeds in the inner reaction layer are found to agree very well with the laminar R-to-P calculations over a wide range of strain for higher Damkhler number conditions, well beyond the regime in which agreement was expected. For lower Damkhler numbers, a reduced response to strain is observed, consistent with previous studies and theoretical expectations. Compared with the inner layer, broader and shifted probability density functions (PDFs) of displacement speed were observed in the fresh gases, and the agreement with the R-to-P calculations deteriorated. Consumption speeds show a poorer agreement with strained laminar calculations, which is attributed to multidimensional effects and a more attenuated unsteady response to strain fluctuations; however, they

  11. Closure of the Averaged Equations for Disperse Two-Phase Flow by Direct Numerical Simulation: Final Report

    SciTech Connect (OSTI)

    Andrea Prosperetti

    2006-03-24

    The report briefly describes the activities carried out in the course of the project. A first line of research was the development of systematic closure relations for averaged equations for disperse multiphase flow. A second line was the development of efficient numerical methods for the simulation of Navier-Stokes flows with many suspended particles. The report also lists the 21 journal articles in which this work is more fully decsribed.

  12. Development of RAMS-CMAQ to Simulate Aerosol Optical Depth and Aerosol Direct Radiative Forcing and Its Application to East Asia

    SciTech Connect (OSTI)

    Han, Xiao; Zhang, Meigen; Liu, Xiaohong; Ghan, Steven J.; Xin, Jin-Yuan; Wang, Li-Li

    2009-11-16

    The air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multi-scale Air Quality) is developed to simulate the aerosol optical depth (AOD) and aerosol direct forcing (DF). The aerosol-specific extinction, single scattering albedo, and asymmetry factor are parameterized based on Mie theory taking into account the aerosol size distribution, composition, refractive index, and water uptake of solution particles. A two-stream solar radiative model considers all gaseous molecular absorption, Rayleigh scattering, and aerosols and clouds. RAMSCMAQ is applied to simulate all major aerosol concentrations (e.g., sulfate, nitrate, ammonium, organic carbon, black carbon, fine soil, and sea salt) and AOD and DF over East Asia in 2005. To evaluate its performance, the simulated AOD values were compared with ground-based in situ measurements. The comparison shows that RAMSCMAQ performed well in most of the model domain and generally captured the observed variations. High AOD values (0.2−1.0) mainly appear in the Sichuan Basin as well as in central and southeastern China. The geographic distribution of DF generally follows the AOD distribution patterns, and the DF at the top-of-the-atmosphere is less than −25 and −20 W m−2 in clear-sky and all-sky over the Sichuan Basin. Both AOD and DF exhibit seasonal variations with lower values in July and higher ones in January. The DF could obviously be impacted by high cloud fractions.

  13. UNDERSTANDING SDO/AIA OBSERVATIONS OF THE 2010 JUNE 13 EUV WAVE EVENT: DIRECT INSIGHT FROM A GLOBAL THERMODYNAMIC MHD SIMULATION

    SciTech Connect (OSTI)

    Downs, Cooper; Roussev, Ilia I.; Lugaz, Noe; Van der Holst, Bart; Sokolov, Igor V.

    2012-05-10

    In this work, we present a comprehensive observation and modeling analysis of the 2010 June 13 extreme-ultraviolet (EUV) wave observed by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). Due to extreme advances in cadence, resolution, and bandpass coverage in the EUV regime, the AIA instrument offers an unprecedented ability to observe the dynamics of large-scale coronal wave-like transients known as EUV waves. To provide a physical analysis and further complement observational insight, we conduct a three-dimensional, time-dependent thermodynamic MHD simulation of the eruption and associated EUV wave, and employ forward modeling of EUV observables to compare the results directly observations. We focus on two main aspects: (1) the interpretation of the stark thermodynamic signatures in the multi-filter AIA data within the propagating EUV wave front, and (2) an in-depth analysis of the simulation results and their implication with respect to EUV wave theories. Multiple aspects, including the relative phases of perturbed variables, suggest that the outer, propagating component of the EUV transient exhibits the behavior of a fast-mode wave. We also find that this component becomes decoupled from the evolving structures associated with the coronal mass ejection that are also visible, providing a clear distinction between wave and non-wave mechanisms at play.

  14. IN-VEHICLE, HIGH-POWER ENERGY STORAGE SYSTEMS

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Properties of Uni-directionally Reinforced Hybrid Fiber Composites, " MS thesis in Engineering Mechanics, The Pennsylvania State University, Aug. 2013. * Ross, J. W., "On...

  15. Directives Tools

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    Useful links and resources for Directives Writers, Directives Point of Contact (DPCs), Subject Matter Experts (SMEs), and Draft Directive Reviewers.

  16. Assessment of multi-decadal WRF-CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-07-01

    Multi-decadal simulations with the coupled WRF-CMAQ model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 21 years (1990–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analyses conducted by Gan et al. (2014) utilizingmore » observations (e.g. SURFRAD, CASTNET, IMPROVE and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF-CMAQ model is capable of replicating the trends well even through it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrenpancies found in the clear-sky diffuse SW radiation are likely due to several factors such as potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval methodology and aerosol semi-direct and/or indirect effects which cannot be

  17. Assessment of long-term WRF–CMAQ simulations for understanding direct aerosol effects on radiation "brightening" in the United States

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gan, C.-M.; Pleim, J.; Mathur, R.; Hogrefe, C.; Long, C. N.; Xing, J.; Wong, D.; Gilliam, R.; Wei, C.

    2015-11-03

    Long-term simulations with the coupled WRF–CMAQ (Weather Research and Forecasting–Community Multi-scale Air Quality) model have been conducted to systematically investigate the changes in anthropogenic emissions of SO2 and NOx over the past 16 years (1995–2010) across the United States (US), their impacts on anthropogenic aerosol loading over North America, and subsequent impacts on regional radiation budgets. In particular, this study attempts to determine the consequences of the changes in tropospheric aerosol burden arising from substantial reductions in emissions of SO2 and NOx associated with control measures under the Clean Air Act (CAA) especially on trends in solar radiation. Extensive analysesmore » conducted by Gan et al. (2014a) utilizing observations (e.g., SURFRAD, CASTNET, IMPROVE, and ARM) over the past 16 years (1995–2010) indicate a shortwave (SW) radiation (both all-sky and clear-sky) "brightening" in the US. The relationship of the radiation brightening trend with decreases in the aerosol burden is less apparent in the western US. One of the main reasons for this is that the emission controls under the CAA were aimed primarily at reducing pollutants in areas violating national air quality standards, most of which were located in the eastern US, while the relatively less populated areas in the western US were less polluted at the beginning of this study period. Comparisons of model results with observations of aerosol optical depth (AOD), aerosol concentration, and radiation demonstrate that the coupled WRF–CMAQ model is capable of replicating the trends well even though it tends to underestimate the AOD. In particular, the sulfate concentration predictions were well matched with the observations. The discrepancies found in the clear-sky diffuse SW radiation are likely due to several factors such as the potential increase of ice particles associated with increasing air traffic, the definition of "clear-sky" in the radiation retrieval

  18. Directives System

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1998-01-30

    The Department of Energy (DOE) Directives System is the means by which DOE policies, requirements, and responsibilities are developed and communicated throughout the Department. Directives are used to inform, direct, and guide employees in the performance of their jobs, and to enable employees to work effectively within the Department and with agencies, contractors, and the public. Cancels: DOE O 251.1, DOE M 251.1-1

  19. Strategic Direction

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Volume One Film Collection Volume Two 75th Anniversary Hydropower in the Northwest Woody Guthrie Videos Strategic Direction Branding & Logos Power of the River History Book...

  20. DRIVING DIRECTIONS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    South Alamo Street San Antonio, Texas 78205 (210) 222-1400 San Antonio International Airport DIRECTIONS Take Interstate 281 south to Commerce Street. Continue west on Commerce...

  1. Directives Help

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    All DOE directives are available through this site. While it may seem overwhelming, given the number of documents, we have provided a number of ways in which you may get to the information you need.

  2. Direct Frisk

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Direct Federal Financial Interventions and Subsidies in Energy in Fiscal Year 2013 March 2015 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 U.S. Energy Information Administration | Direct Federal Financial Interventions and Subsidies in Energy in Fiscal Year 2013 i This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and analytical agency within the U.S. Department of Energy. By law, EIA's data, analyses,

  3. Directives Tools - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Guides (Text version available here) Cancelling a Directive New Canceling a Directive The process for canceling directives (Text version available here) Directives Templates...

  4. DIRECTIONAL COUPLERS

    DOE Patents [OSTI]

    Nigg, D.J.

    1961-12-01

    A directional coupler of small size is designed. Stripline conductors of non-rectilinear configuration, and separated from each other by a thin dielectric spacer. cross each other at least at two locations at right angles, thus providing practically pure capacitive coupling which substantially eliminates undesirable inductive coupling. The conductors are sandwiched between a pair of ground planes. The coupling factor is dependent only on the thickness and dielectric constant of the dielectric spacer at the point of conductor crossover. (AEC)

  5. DIRECTIONAL ANTENNA

    DOE Patents [OSTI]

    Bittner, B.J.

    1958-05-20

    A high-frequency directional antenna of the 360 d scaring type is described. The antenna has for its desirable features the reduction in both size and complexity of the mechanism for rotating the antenna through its scanning movement. These advantages result from the rotation of only the driven element, the reflector remaining stationary. The particular antenna structure comprises a refiector formed by a plurality of metallic slats arranged in the configuration of an annular cage having the shape of a zone of revolution. The slats are parallel to each other and are disposed at an angle of 45 d to the axis of the cage. A directional radiator is disposed inside the cage at an angle of 45 d to the axis of the cage in the same direction as the reflecting slats which it faces. As the radiator is rotated, the electromagnetic wave is reflected from the slats facing the radiator and thereafter passes through the cage on the opposite side, since these slats are not parallel with the E vector of the wave.

  6. Large Eddy Simulations: Where

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Eddy Simulations: Where observations and modeling collides July 18, 2015 Cascade of Models ⌅ General Circulation Models ⌅ Regional Models ⌅ Large-Eddy SimulationsDirect Numerical Simulations LES GCM vs LES History Theory What if? Using LES together with Observations Testbed LES 2 / 37 Cascade of Models General Circulation Models ⌅ Domain size: Entire Earth ⌅ Horizontal Boundary conditions: None ⌅ Horizontal grid spacing: 50km ⌅ Total number of points: about 400 ⇥ 400 ⇥ 100

  7. MHK Technologies/LUKAS | Open Energy Information

    Open Energy Info (EERE)

    left an or front back or high down to a uni directional one way horizontal push These energies are free renewable but still undeveloped yet in navigations Mooring Configuration...

  8. Simulators IV

    SciTech Connect (OSTI)

    Fairchild, B.T.

    1987-01-01

    These proceedings contain papers on simulators with artificial intelligence, and the human decision making process; visuals for simulators: human factors, training, and psycho-physical impacts; the role of institutional structure on simulation projects; maintenance trainers for economic value and safety; biomedical simulators for understanding nature, for medical benefits, and the physiological effects of simulators; the mathematical models and numerical techniques that drive today's simulators; and the demography of simulators, with census papers identifying the population of real-time simulator training devices; nuclear reactors.

  9. Directives Templates - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and format Directives Templates Justification Memoranda Per Secretarial Memo, Enterprise Risk Management (ERM) Framework for Directives, dated July 9, 2012, by September 1, 2012,...

  10. An Integrated Platform for Engine Performance Simulations and...

    Broader source: Energy.gov (indexed) [DOE]

    The direct injection stochastic reactor model is capable of accurate simulation of combustion under diesel conditions and can also be used to simulate and test different fuels. ...

  11. Numerical simulations for low energy nuclear reactions including...

    Office of Scientific and Technical Information (OSTI)

    Numerical simulations for low energy nuclear reactions including direct channels to validate statistical models Citation Details In-Document Search Title: Numerical simulations for ...

  12. Directives - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directives Current Directives List Directives are the Department of Energy's primary means of establishing policies, requirements, responsibilities, and procedures for Departmental elements and contractors Current Draft Archives by Website Administrator More filters Less filters Directive Type Order Guide Manual Policy Notice Cancellation Notice HQ Order Sec of Energy Notice Justification Memorandum Certification Memo 0 Series Series All 0000 Subject Classification 100 Leadership/Management

  13. Directives Tools - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directives Tools by Website Administrator Title Author Type Modified Processing a Policy or Notice Website Administrator Page Feb 26, 2014 09:17 AM Types of Directives Website Administrator Page Jan 10, 2014 10:16 AM Crosswalk of Directives Numbering System Website Administrator File Mar 26, 2014 01:41 PM Directives Templates Website Administrator Page Jun 30, 2016 12:19 PM Implementation Plan Template Website Administrator File Jan 10, 2014 01:20 PM Directives Certification Letter Website

  14. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The following new and revised Directives are available over the Internet on the Office of Management's home page for Directives at: https:www.directives.doe.gov...

  15. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-08-16

    The Order is the primary directive for administering the Department's directives Program. Cancels: DOE O 251.1A

  16. New directions in mechanics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kassner, Michael E.; Nemat-Nasser, Sia; Suo, Zhigang; Bao, Gang; Barbour, J. Charles; Brinson, L. Catherine; Espinosa, Horacio; Gao, Huajian; Granick, Steve; Gumbsch, Peter; et al

    2004-09-15

    The Division of Materials Sciences and Engineering of the US Department of Energy (DOE) sponsored a workshop to identify cutting-edge research needs and opportunities, enabled by the application of theoretical and applied mechanics. The workshop also included input from biochemical, surface science, and computational disciplines, on approaching scientific issues at the nanoscale, and the linkage of atomistic-scale with nano-, meso-, and continuum-scale mechanics. This paper is a summary of the outcome of the workshop, consisting of three main sections, each put together by a team of workshop participants. Section 1 addresses research opportunities that can be realized by the applicationmore » of mechanics fundamentals to the general area of self-assembly, directed self-assembly, and fluidics. Section 2 examines the role of mechanics in biological, bioinspired, and biohybrid material systems, closely relating to and complementing the material covered in Section 1. In this manner, it was made clear that mechanics plays a fundamental role in understanding the biological functions at all scales, in seeking to utilize biology and biological techniques to develop new materials and devices, and in the general area of bionanotechnology. While direct observational investigations are an essential ingredient of new discoveries and will continue to open new exciting research doors, it is the basic need for controlled experimentation and fundamentally- based modeling and computational simulations that will be truly empowered by a systematic use of the fundamentals of mechanics. Section 3 brings into focus new challenging issues in inelastic deformation and fracturing of materials that have emerged as a result of the development of nanodevices, biopolymers, and hybrid bio–abio systems. As a result, each section begins with some introductory overview comments, and then provides illustrative examples that were presented at the workshop and which are believed to highlight the

  17. Recently Canceled Directives - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Requirements Recently Canceled Directives Directives and other requirements documents canceled in the last 90 days. All Recently Issued/Updated Recently Canceled Directives Recently Rescinded Delegations by Website Administrator More filters Less filters Filters applied Δ Hide filters ∇ Show filters (0) [X] Remove all Document Type Cancellation Notice Certification Memo Delegation Designation Guide HQ Order Invoked Technical Standards Justification Memorandum Manual Notice Order

  18. Directives Help - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Help by Website Administrator All DOE directives are available through this site. While it may seem overwhelming, given the number of documents, we have provided a number of ways in which you may get to the information you need. Navigating the DOE Directives, Delegations, and Requirements Portal A guide for using the new portal is available here. Navigation Tools The links at the top of the page will take you to the major elements of the site--directives, delegations and requirements. The

  19. Multiple direction vibration fixture

    DOE Patents [OSTI]

    Cericola, Fred; Doggett, James W.; Ernest, Terry L.; Priddy, Tommy G.

    1991-01-01

    An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

  20. Directives Requiring Additional Documentation - DOE Directives,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Delegations, and Requirements Requiring Additional Documentation by Website Administrator PDF document icon DirectivesRequiringAdditionalDocumentation (1).pdf - PDF document, 35 KB (36219

  1. Laboratory Directed Research and Development - DOE Directives...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2C, Laboratory Directed Research and Development by Russell Ames Functional areas: Energy Research & Technology To establish Department of Energy (DOE) requirements for laboratory...

  2. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Management's home page for Directives at https:www.directives.doe.govdirectives APRIL 2015 DOE O 325.2, Position Management and Classification The order establishes ...

  3. Directives Quarterly Updates

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    Listings of new Justification Memoranda and new or revised Directives that have been posted to the DOE Directives, Delegations, and Requirements Portal. Updated quarterly.

  4. direct_deposit_111609

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PROTECT YOUR BANKING INFORMATION: DO NOT complete this form until you are ready to submit it to the Payroll Department. DIRECT DEPOSIT REQUEST Directions: 1. Provide required information neatly, legibly; 2. If Checking Account Direct Deposit, include a voided check. a. DO NOT submit a deposit slip! 3. If Savings Account Direct Deposit, include a copy of savings card. 4. Sign this form; 5. Inter-office mail it to Craft Payroll at "P238." DIRECT DEPOSITION AUTHORIZATION I hereby

  5. Buckman Direct Diversion Project

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Buckman Direct Diversion Project Buckman Direct Diversion Project This project takes surface water from the Rio Grande, and then treats and distributes these waters to the city and county of Santa Fe through their drinking water distribution systems. August 1, 2013 Water flumes at Buckman Direct Diversion Project Water flumes at Buckman Direct Diversion Project The City of Santa Fe and Santa Fe County completed the construction of the Buckman Direct Diversion (BDD) Project in December 2010. The

  6. Departmental Directives Program Manual - DOE Directives, Delegations...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    M 251.1-1B, Departmental Directives Program Manual by Website Administrator Functional areas: Information Technology, The Manual supplements DOE O 251.1B. Cancels DOE M 251.1-1A....

  7. Wind Simulation

    Energy Science and Technology Software Center (OSTI)

    2008-12-31

    The Software consists of a spreadsheet written in Microsoft Excel that provides an hourly simulation of a wind energy system, which includes a calculation of wind turbine output as a power-curve fit of wind speed.

  8. Directives Certification Letter - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directives & Documents Directives & Documents Policy & Guidance Policy & Guidance contains Project Management related orders, guides, handbooks, templates, standard operating procedures, and industry standards that allow Federal Project Directors and project teams to comply with applicable laws and regulations while putting in place most effective project managemetn practices that increase probability of project success. Proceed to Policy & Guidance >> Publications

  9. Directional recoil rates for WIMP direct detection

    SciTech Connect (OSTI)

    Alenazi, Moqbil S.; Gondolo, Paolo [Department of Physics, University of Utah, 115 S 1400 E Rm 201, Salt Lake City, Utah 84112-0830 (United States)

    2008-02-15

    New techniques for the laboratory direct detection of dark matter weakly interacting massive particles (WIMPs) are sensitive to the recoil direction of the struck nuclei. We compute and compare the directional recoil rates dR/dcos{theta} (where {theta} is the angle measured from a reference direction in the sky) for several WIMP velocity distributions including the standard dark halo and anisotropic models such as Sikivie's late-infall halo model and logarithmic-ellipsoidal models. Since some detectors may be unable to distinguish the beginning of the recoil track from its end (lack of head-tail discrimination), we introduce a folded directional recoil rate dR/d|cos{theta}|, where |cos{theta}| does not distinguish the head from the tail of the track. We compute the CS{sub 2} and CF{sub 4} exposures required to distinguish a signal from an isotropic background noise, and find that dR/d|cos{theta}| is effective for the standard dark halo and some but not all anisotropic models.

  10. Direct/Indirect Costs

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28

    This chapter provides recommended categories for direct and indirect elements developed by the Committee for Cost Methods Development (CCMD) and describes various estimating techniques for direct and indirect costs.

  11. Direct process for explosives

    DOE Patents [OSTI]

    Akst, I.B.; Stinecipher, M.M.

    1982-10-12

    A direct process of making ethylenediamine dinitrate through the reaction of ethylenediamine and ammonium nitrate is described.

  12. Directives System Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1998-01-30

    This Manual provides detailed requirements to supplement DOE O 251.1A, Directives System, dated 1-30-98.

  13. About Direct Current

    Broader source: Energy.gov [DOE]

    Learn about Direct Current -- a podcast about the energy that lights our homes, powers our lives and shapes our world.

  14. Directives Quarterly Updates - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Requirements Quarterly Updates by Diane Johnson Listings of new Justification Memoranda and new or revised Directives that have been posted to the DOE Directives, Delegations, and Requirements Portal. Updated quarterly. FY2016 FY 16, Q2 - January through March 2016 FY2015 FY15, Q1 - October through December 2014 FY15, Q3 - April through June 2015 FY15, Q4 - July through September 2015 FY 2014 FY14, Q1 - October through December 2013 FY14, Q2 - January through March 2014 FY14, Q3 - April

  15. Direct Numerical Simulations of Flame Propagation in Hydrogen-Oxygen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mixtures in Closed Vessels | Argonne Leadership Computing Facility Weak ignition behind a reflected shock in 2H2+O2 mixture Weak ignition behind a reflected shock in 2H2+O2 mixture at initially atmospheric pressure. The figure shows a two-dimensional distribution of density in the middle of a shock tube with a square cross-section of 5 cm x 5 cm. The end wall of the tube is on the right. The reflected bifurcated shock is on the left and is moving to the left. Weak ignition took place near

  16. Direct Numerical Simulations and Robust Predictions of Cloud...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    vortical flows. Project researchers will use their award-winning, two-phase compressible flow code, CUBISM-MPCF, to capture the collapse of more than 50,000 bubbles...

  17. MESOSCALE SIMULATIONS OF POWDER COMPACTION

    SciTech Connect (OSTI)

    Lomov, Ilya; Fujino, Don; Antoun, Tarabay; Liu, Benjamin

    2009-12-28

    Mesoscale 3D simulations of shock compaction of metal and ceramic powders have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating a well-characterized shock compaction experiment of a porous ductile metal. Simulation results using the Steinberg material model and handbook values for solid 2024 aluminum showed good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not as well studied as metals, so a simple material model for solid ceramic (tungsten carbide) has been calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powders have been performed and showed good agreement with experimental data. The numerical shock wave profile has same character and thickness as that measured experimentally using VISAR. The numerical results show reshock states above the single-shock Hugoniot line as observed in experiments. We found that for good quantitative agreement with experiments 3D simulations are essential.

  18. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2007-09-10

    To define requirements and responsibilities for implementing the Department of Energy (DOE) Directives Program in support of the Secretary's memorandum of September 10, 2007, Principles Governing Departmental Directives. See also the current list of Directives Requiring Further Documentation, as required by Appendix D of this Order. Supersedes DOE P 251.1A, DOE O 251.1B, DOE M 251.1-1B.

  19. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    https:www.directives.doe.govdirectivesdirectives July 2013 DOE O 243.1B Admin Chg 1, Records Management Program - The order sets forth requirements and responsibilities for ...

  20. Direct Research & Development Transactions

    Broader source: Energy.gov [DOE]

    DOE direct research and development transactions include contracts, grants, and cooperative agreements, and technology investment agreements (TIA’s). For transactions other than TIA’s, the US...

  1. Cancellation of Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2016-05-26

    Effective immediately the following Department of Energy directive is canceled: DOE P 111.1, Departmental Organization Management System, dated 08-27-96.

  2. Cancellation of Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-01-26

    Effective immediately the following Department of Energy directive is canceled. DOE M 452.2-2, Nuclear Explosive Safety Evaluation Processes, dated 04-14-2009.

  3. Directives System Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-16

    This Manual provides detailed requirements to supplement DOE O 251.1, which establishes requirements for the development, coordination, and sunset review of DOE directives.

  4. BACnet's Future Directions

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and building controllers BACnet International has developed and deployed a BACnet ... technologies. Future Directions Smart Grid Cyber- Security Moving Forward Integration

  5. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2014-10-16

    To establish directives as the primary means to set, communicate, and institutionalize policies, requirements, responsibilities, and procedures for Departmental elements and contractors.

  6. Direct-fired biomass

    SciTech Connect (OSTI)

    None, None

    2009-01-18

    The direct-fired biomass section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  7. Atom-diatom scattering dynamics of spinning molecules

    SciTech Connect (OSTI)

    Eyles, C. J.; Flo, J.; Averbukh, I. Sh.; Leibscher, M.

    2015-01-14

    We present full quantum mechanical scattering calculations using spinning molecules as target states for nuclear spin selective atom-diatom scattering of reactive D+H{sub 2} and F+H{sub 2} collisions. Molecules can be forced to rotate uni-directionally by chiral trains of short, non-resonant laser pulses, with different nuclear spin isomers rotating in opposite directions. The calculations we present are based on rotational wavepackets that can be created in this manner. As our simulations show, target molecules with opposite sense of rotation are predominantly scattered in opposite directions, opening routes for spatially and quantum state selective scattering of close chemical species. Moreover, two-dimensional state resolved differential cross sections reveal detailed information about the scattering mechanisms, which can be explained to a large degree by a classical vector model for scattering with spinning molecules.

  8. Departmental Directives System

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1983-04-07

    The order establishes the directives system to be used for publishing permanent and temporary directives issued by DOE Headquarters and addressed to Headquarters and/or field elements. Chg 1 dated 3-14-85. Cancels DOE 1321.1A.

  9. Hybrid Simulator

    Energy Science and Technology Software Center (OSTI)

    2005-10-15

    HybSim (short for Hybrid Simulator) is a flexible, easy to use screening tool that allows the user to quanti the technical and economic benefits of installing a village hybrid generating system and simulates systems with any combination of —Diesel generator sets —Photovoltaic arrays -Wind Turbines and -Battery energy storage systems Most village systems (or small population sites such as villages, remote military bases, small communities, independent or isolated buildings or centers) depend on diesel generationmore » systems for their source of energy. HybSim allows the user to determine other "sources" of energy that can greatly reduce the dollar to kilo-watt hour ratio. Supported by the DOE, Energy Storage Program, HybSim was initially developed to help analyze the benefits of energy storage systems in Alaskan villages. Soon after its development, other sources of energy were added providing the user with a greater range of analysis opportunities and providing the village with potentially added savings. In addition to village systems, HybSim has generated interest for use from military institutions in energy provisions and USAID for international village analysis.« less

  10. Direct nuclear pumped laser

    DOE Patents [OSTI]

    Miley, George H.; Wells, William E.; DeYoung, Russell J.

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  11. Departmental Directives Program

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-08-13

    The order establishes directives as the primary means to set, communicate, and institutionalize policies, requirements, responsibilities, and procedures for Departmental elements and contractors. The second draft is being submitted for review owing to extensive revisions to the first draft.

  12. Directives Quarterly Update

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    https:www.directives.doe.govdirectives-browsec8- operatoror&c10&c12&bstart0 January 2014 DOE O 343.1, Federal Substance Abuse Testing Program - The Order establishes the ...

  13. AISI direct steelmaking program

    SciTech Connect (OSTI)

    Aukrust, E.

    1991-01-09

    AISI with co-funding from DOE has initiated a research and development program aimed at the development of a new process for direct steelmaking, and the program is discussed in this document. The project is expected to cost about $30 million over a three-year period, with the government providing approximately 77 percent of the funds and AISI the balance. In contrast to current steelmaking processes which are largely open and batch, the direct steelmaking process would be closed and continuous. Further, it would use coal directly, thereby avoiding the need for coke ovens. The second year of the Direct Steelmaking Program (November 29, 1989, through November 28, 1990) was a year of significant accomplishment. The various research programs proceeded essentially on schedule and the pilot plant, the centerpiece of the program, was completed about three months behind schedule but began operation in almost a picture-perfect manner. This report presents the last years accomplishments.

  14. Numerical simulations for low energy nuclear reactions including...

    Office of Scientific and Technical Information (OSTI)

    Numerical simulations for low energy nuclear reactions including direct channels to ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  15. Mesoscale Simulations of Particulate Flows with Parallel Distributed...

    Office of Scientific and Technical Information (OSTI)

    Visit OSTI to utilize additional information resources in energy science and technology. A ... We propose a computational technique based on the direct numerical simulation of the ...

  16. Refrigerant directly cooled capacitors

    DOE Patents [OSTI]

    Hsu, John S.; Seiber, Larry E.; Marlino, Laura D.; Ayers, Curtis W.

    2007-09-11

    The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

  17. Directions - 88-Inch Cyclotron

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Directions The Laboratory is on the hillside directly above the campus of the University of California at Berkeley. Our address is 1 Cyclotron Rd. Bldg. 88, Berkeley, CA 94720. To make the Lab easily accessible, the Lab has its own shuttle service that takes people around the site, to downtown Berkeley, and to the BART station. Parking spaces can sometimes be difficult to find at the 88-Inch Cyclotron, so make sure to prearrange for a parking permit with our Administrative Office. Further

  18. Energy Simulator Residential Buildings

    Energy Science and Technology Software Center (OSTI)

    1992-02-24

    SERI-RES performs thermal energy analysis of residential or small commercial buildings and has the capability of modeling passive solar equipment such as rock beds, trombe walls, and phase change material. The analysis is accomplished by simulation. A thermal model of the building is created by the user and translated into mathematical form by the program. The mathematical equations are solved repeatedly at time intervals of one hour or less for the period of simulation. Themore » mathematical representation of the building is a thermal network with nonlinear, temperature-dependent controls. A combination of forward finite differences, Jacobian iteration, and constrained optimization techniques is used to obtain a solution. An auxiliary interactive editing program, EDITOR, is included for creating building descriptions. EDITOR checks the validity of the input data and also provides facilities for storing and referencing several types of building description files. Some of the data files used by SERI-RES need to be implemented as direct-access files. Programs are included to convert sequential files to direct-access files and vice versa.« less

  19. Direct conversion technology

    SciTech Connect (OSTI)

    Massier, P.F.; Back, L.H.; Ryan, M.A.; Fabris, G.

    1992-01-07

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. This report contains progress of research on the Alkali Metal Thermal-to-Electric Converter (AMTEC) and on the Two-Phase Liquid-Metal MHD Electrical Generator (LMMHD) for the period January 1, 1991 through December 31, 1991. Research on AMTEC and on LMMHD was initiated during October 1987. Reports prepared on previous occasions (Refs. 1--5) contain descriptive and performance discussions of the following direct conversion concepts: thermoelectric, pyroelectric, thermionic, thermophotovoltaic, thermoacoustic, thermomagnetic, thermoelastic (Nitionol heat engine); and also, more complete descriptive discussions of AMTEC and LMMHD systems.

  20. Highly directional thermal emitter

    DOE Patents [OSTI]

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  1. Direct Conversion Technology

    SciTech Connect (OSTI)

    Back, L.H.; Fabris, G.; Ryan, M.A.

    1992-07-01

    The overall objective of the Direct Conversion Technology task is to develop an experimentally verified technology base for promising direct conversion systems that have potential application for energy conservation in the end-use sectors. Initially, two systems were selected for exploratory research and advanced development. These are Alkali Metal Thermal-to-Electric Converter (AMTEC) and Two-Phase Liquid Metal MD Generator (LMMHD). This report describes progress that has been made during the first six months of 1992 on research activities associated with these two systems. (GHH)

  2. Directions & Maps

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Information » Directions & Maps Directions & Maps The Bradbury Science Museum is located in downtown Los Alamos at the corner of Central Avenue and 15th Street. Contact Us thumbnail of 1350 Central Avenue Bradbury Science Museum 1350 Central Avenue 505 667-4444 Email Where we're located Los Alamos (elevation 7,355 feet) is perched high atop the Pajarito Plateau in the Jemez Mountains, 35 miles northwest of Santa Fe. The Bradbury Science Museum is located in downtown Los Alamos at the

  3. Directed Quantum Chaos

    SciTech Connect (OSTI)

    Efetov, K.B. [Max-Planck Institut fuer Physik komplexer Systeme, Heisenbergstrasse 1, 70569 Stuttgart (Germany)] [Max-Planck Institut fuer Physik komplexer Systeme, Heisenbergstrasse 1, 70569 Stuttgart (Germany); [L.D. Landau Institute for Theoretical Physics, Moscow (Russia)

    1997-07-01

    Quantum disordered problems with a direction (imaginary vector potential) are discussed and mapped onto a supermatrix {sigma} model. It is argued that the 0D version of the {sigma} model may describe a broad class of phenomena that can be called directed quantum chaos. It is demonstrated by explicit calculations that these problems are equivalent to those of random asymmetric or non-Hermitian matrices. A joint probability of complex eigenvalues is obtained. The fraction of states with real eigenvalues proves to be always finite for time reversal invariant systems. {copyright} {ital 1997} {ital The American Physical Society}

  4. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect (OSTI)

    Hossein Ghezel-Ayagh

    2003-05-22

    Project activities were focused on the design and construction the sub-scale hybrid Direct Fuel Cell/turbine (DFC/T{reg_sign}) power plant and modification of a Capstone Simple Cycle Model 330 microturbine. The power plant design work included preparation of system flow sheet and performing computer simulations based on conservation of mass and energy. The results of the simulation analyses were utilized to prepare data sheets and specifications for balance-of-plant equipment. Process flow diagram (PFD) and piping and instrumentation diagrams (P&ID) were also completed. The steady state simulation results were used to develop design information for modifying the control functions, and for sizing the heat exchangers required for recuperating the waste heat from the power plant. Line and valve sizes for the interconnecting pipes between the microturbine and the heat recuperators were also identified.

  5. Peptide partitioning properties from direct insertion studies

    SciTech Connect (OSTI)

    Ulmschneider, Martin [University of Oxford; Smith, Jeremy C [ORNL; Ulmschneider, Jakob [University of Heidelberg

    2010-06-01

    Partitioning properties of polypeptides are at the heart of biological membrane phenomena and their precise quantification is vital for ab-initio structure prediction and the accurate simulation of membrane protein folding and function. Recently the cellular translocon machinery has been employed to determine membrane insertion propensities and transfer energetics for a series of polyleucine segments embedded in a carrier sequence. We show here that the insertion propensity, pathway, and transfer energetics into synthetic POPC bilayers can be fully described by direct atomistic peptide partitioning simulations. The insertion probability as a function of peptide length follows two-state Boltzmann statistics, in agreement with the experiments. The simulations expose a systematic offset between translocon-mediated and direct insertion free energies. Compared to the experiment the insertion threshold is shifted toward shorter peptides by 2 leucine residues. The simulations reveal many hitherto unknown atomic-resolution details about the partitioning process and promise to provide a powerful tool for urgently needed calibration of lipid parameters to match experimentally observed peptide transfer energies.

  6. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-02-12

    The following directives are extended until 8-12-04. DOE N 205.2, Foreign National Access to DOE Cyber Systems, dated 11/1/99. DOE N 205.3, Password Generation, Protection, and Use, dated 11/23/99.

  7. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2003-02-24

    This Notice extends the following directives until 2/16/04: DOE N 205.2, Foreign National Access to DOE Cyber Systems, and DOE N 205.3, Password Generation, Protection, and Use, dated 11/23/99-7/1/00.

  8. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-08-12

    The following directives are extended until 8-12-05: DOE N 205.2, Foreign National Access to DOE Cyber Security Systems, dated 11-1-99 and DOE N 205.3, Password Generation, Protection, and Use, dated 11-23-99. No cancellations.

  9. Directional gamma detector

    DOE Patents [OSTI]

    LeVert, Francis E.; Cox, Samson A.

    1981-01-01

    An improved directional gamma radiation detector has a collector sandwiched etween two layers of insulation of varying thicknesses. The collector and insulation layers are contained within an evacuated casing, or emitter, which releases electrons upon exposure to gamma radiation. Delayed electrons and electrons entering the collector at oblique angles are attenuated as they pass through the insulation layers on route to the collector.

  10. Direct fired heat exchanger

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  11. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2006-10-10

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  12. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Jesse, Stowell; Costin, Daniel

    2007-02-27

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  13. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-07-11

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  14. Direct drive wind turbine

    DOE Patents [OSTI]

    Bywaters, Garrett Lee; Danforth, William; Bevington, Christopher; Stowell, Jesse; Costin, Daniel

    2006-09-19

    A wind turbine is provided that minimizes the size of the drive train and nacelle while maintaining the power electronics and transformer at the top of the tower. The turbine includes a direct drive generator having an integrated disk brake positioned radially inside the stator while minimizing the potential for contamination. The turbine further includes a means for mounting a transformer below the nacelle within the tower.

  15. Direct hydrocarbon fuel cells

    DOE Patents [OSTI]

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  16. Letter: Direction and Guidance for Implementing Direct DOE Relationship &

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Funding for EMSSABs | Department of Energy Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs Letter: Direction and Guidance for Implementing Direct DOE Relationship & Funding for EMSSABs From: Assistant Secretary, Jessie Hill Roberson (EM-11) To: Mr. Monte Wilson, Chair, INEEL Citizens Advisory Board This letter is in response to a November 21, 2003 letter regarding direction and guidance for implementing direct DOE relationship and funding

  17. Direct Observation of the Transition from Indirect to Direct...

    Office of Scientific and Technical Information (OSTI)

    Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin ... Sponsoring Org: US DOE Office of Science (DOE SC) Country of Publication: United States ...

  18. Direct Observation of the Transition from Indirect to Direct...

    Office of Scientific and Technical Information (OSTI)

    Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  19. Oil spreading in surface waters with an ice cover

    SciTech Connect (OSTI)

    Yapa, P.D.; Weerasuriya, S.A.; Belaskas, D.P.; Chowdhury, T.

    1993-02-01

    A study of oil spreading in surface waters in the presence of a floating ice cover is presented. The ice can be solid or fragmented. Both axi-symmetrical and uni-directional spreading are studied. The report describes the analytical and numerical model development, the experimental set-up, results from the laboratory experiments, and their comparison with the derived theory and the numerical simulation. To analyze the spreading of oil under solid ice, new equations are derived. These equations consider gravity (buoyancy) - inertia phase, gravity (buoyancy) - viscous phase, and the termination of spreading during the buoyancy - surface tension phase. The derivation considers both the constant discharge mode and the constant volume mode. Therefore, a complete description of the spreading phenomena from the time of initial spill to termination of spreading is presented. The emphasis of the study is on the dominant spreading mechanism for oil under ice, which is the buoyancy-viscous phase.

  20. Plasma Simulation Program

    SciTech Connect (OSTI)

    Greenwald, Martin

    2011-10-04

    Many others in the fusion energy and advanced scientific computing communities participated in the development of this plan. The core planning team is grateful for their important contributions. This summary is meant as a quick overview the Fusion Simulation Program's (FSP's) purpose and intentions. There are several additional documents referenced within this one and all are supplemental or flow down from this Program Plan. The overall science goal of the DOE Office of Fusion Energy Sciences (FES) Fusion Simulation Program (FSP) is to develop predictive simulation capability for magnetically confined fusion plasmas at an unprecedented level of integration and fidelity. This will directly support and enable effective U.S. participation in International Thermonuclear Experimental Reactor (ITER) research and the overall mission of delivering practical fusion energy. The FSP will address a rich set of scientific issues together with experimental programs, producing validated integrated physics results. This is very well aligned with the mission of the ITER Organization to coordinate with its members the integrated modeling and control of fusion plasmas, including benchmarking and validation activities. [1]. Initial FSP research will focus on two critical Integrated Science Application (ISA) areas: ISA1, the plasma edge; and ISA2, whole device modeling (WDM) including disruption avoidance. The first of these problems involves the narrow plasma boundary layer and its complex interactions with the plasma core and the surrounding material wall. The second requires development of a computationally tractable, but comprehensive model that describes all equilibrium and dynamic processes at a sufficient level of detail to provide useful prediction of the temporal evolution of fusion plasma experiments. The initial driver for the whole device model will be prediction and avoidance of discharge-terminating disruptions, especially at high performance, which are a critical

  1. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Site map An overview of the available content on this site. Keep the pointer still over an item for a few seconds to get its description. Directives Delegations Other Requirements Top 10 Directives Help Directives Tools RevCom

  2. Dynamic Simulation Nuclear Power Plants

    Energy Science and Technology Software Center (OSTI)

    1992-03-03

    DSNP (Dynamic Simulator for Nuclear Power-Plants) is a system of programs and data files by which a nuclear power plant, or part thereof, can be simulated. The acronym DSNP is used interchangeably for the DSNP language, the DSNP libraries, the DSNP precompiler, and the DSNP document generator. The DSNP language is a special-purpose, block-oriented, digital-simulation language developed to facilitate the preparation of dynamic simulations of a large variety of nuclear power plants. It is amore » user-oriented language that permits the user to prepare simulation programs directly from power plant block diagrams and flow charts by recognizing the symbolic DSNP statements for the appropriate physical components and listing these statements in a logical sequence according to the flow of physical properties in the simulated power plant. Physical components of nuclear power plants are represented by functional blocks, or modules. Many of the more complex components are represented by several modules. The nuclear reactor, for example, has a kinetic module, a power distribution module, a feedback module, a thermodynamic module, a hydraulic module, and a radioactive heat decay module. These modules are stored in DSNP libraries in the form of a DSNP subroutine or function, a block of statements, a macro, or a combination of the above. Basic functional blocks such as integrators, pipes, function generators, connectors, and many auxiliary functions representing properties of materials used in nuclear power plants are also available. The DSNP precompiler analyzes the DSNP simulation program, performs the appropriate translations, inserts the requested modules from the library, links these modules together, searches necessary data files, and produces a simulation program in FORTRAN.« less

  3. Recent DOE Directives Changes

    Broader source: Energy.gov [DOE]

    On September 1, 2009, the Department of Energy (DOE) manuals were revised and issued to correspond with the following recent Contractor Requirements Documents (CRDs) changes to the following Directives: DOE M 205.1-8 Administrative Change 1—Cyber Security Incident Management Manual; DOE M 205.1-7 Administrative Change 1—Security Controls for Unclassified Information Systems Manual; DOE M 205.1-6 Administrative Change 1—Media Sanitization Manual; DOE M 205.1-5 Administrative Change 1—Cyber Security Process Requirements Manual

  4. Extension of DOE Directives

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2005-03-18

    The following directives are extended until 3-18-06: DOE N 205.8, Cyber Security Requirements for Wireless Devices and Information Systems, dated 2-11-04; DOE N 205.9, Certification and Accreditation Process for Information Systems Including National Security Systems, dated 02-19-04; DOE N 205.10, Cyber Security Requirements for Risk Management, dated 02-19-04; DOE N 205.11, Security Requirements for Remote Access to DOE and Applicable Contractor Information Technology Systems, dated 2-19-04. DOE N 205.12, Clearing, Sanitizing, and Destroying Information System Storage Media, Memory Devices, and Other Related Hardware, dated 2-19-04.

  5. Omni-directional railguns

    DOE Patents [OSTI]

    Shahinpoor, M.

    1995-07-25

    A device is disclosed for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire. 4 figs.

  6. Omni-directional railguns

    DOE Patents [OSTI]

    Shahinpoor, Mohsen

    1995-01-01

    A device for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.

  7. Remote direct memory access

    DOE Patents [OSTI]

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  8. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  9. Building a Particle Simulator

    SciTech Connect (OSTI)

    Weaver, Brian Phillip; Williams, Brian J.

    2015-10-06

    The purpose of this manuscript is to illustrate how to use the simulator we have developed to generate counts from simulated spectra.

  10. Reframing Accelerator Simulations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Simulations Mori-1.png Key Challenges: Use advanced simulation tools to study the feasibility of plasma-based linear colliders and to optimize conceptual designs. Much of the...

  11. Mesoscale Simulations of Power Compaction

    SciTech Connect (OSTI)

    Lomov, I; Fujino, D; Antoun, T; Liu, B

    2009-08-06

    Mesoscale 3D simulations of metal and ceramic powder compaction in shock waves have been performed with an Eulerian hydrocode GEODYN. The approach was validated by simulating shock compaction of porous well-characterized ductile metal using Steinberg material model. Results of the simulations with handbook values for parameters of solid 2024 aluminum have good agreement with experimental compaction curves and wave profiles. Brittle ceramic materials are not so well studied as metals, so material model for ceramic (tungsten carbide) has been fitted to shock compression experiments of non-porous samples and further calibrated to match experimental compaction curves. Direct simulations of gas gun experiments with ceramic powder have been performed and showed good agreement with experimental data. Numerical shock wave profile has same character and thickness as measured with VISAR. Numerical results show reshock states above the single-shock Hugoniot line also observed in experiments. They found that to receive good quantitative agreement with experiment it is essential to perform 3D simulations.

  12. Site directed recombination

    DOE Patents [OSTI]

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  13. DIRECT CURRENT ELECTROMAGNETIC PUMP

    DOE Patents [OSTI]

    Barnes, A.H.

    1957-11-01

    An improved d-c electromagnetic pump is presented in which the poles, and consequently the magetic gap at the poles, are tapered to be wider at the upstream end. In addition, the cross section of the tube carryiQ the liquid metal is tapered so that the velocity of the pumped liquid increases in the downstream direction at a rate such that the counter-induced voltage in the liquid metal remains constant as it traverses the region between the poles. This configuration compensates for the distortion of the magnetic field caused by the induced voltage that would otherwise result in the lowering of the pumping capacity. This improved electromagnetic pump as practical application in the pumping of liquid metal coolants for nuclear reactors where conventional positive displacement pumps have proved unsatisfactory due to the high temperatures and the corrosive properties of the liquid metals involved.

  14. Directed light fabrication

    SciTech Connect (OSTI)

    Lewis, G.K.; Nemec, R.; Milewski, J.; Thoma, D.J.; Cremers, D.; Barbe, M.

    1994-09-01

    Directed Light Fabrication (DLF) is a rapid prototyping process being developed at Los Alamos National Laboratory to fabricate metal components. This is done by fusing gas delivered metal powder particles in the focal zone of a laser beam that is, programmed to move along or across the part cross section. Fully dense metal is built up a layer at a time to form the desired part represented by a 3 dimensional solid model from CAD software. Machine ``tool paths`` are created from the solid model that command the movement and processing parameters specific to the DLF process so that the part can be built one layer at a time. The result is a fully dense, near net shape metal part that solidifies under rapid solidification conditions.

  15. An Integrated Platform for Engine Performance Simulations and Optimization

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    under Diesel Conditions | Department of Energy An Integrated Platform for Engine Performance Simulations and Optimization under Diesel Conditions An Integrated Platform for Engine Performance Simulations and Optimization under Diesel Conditions The direct injection stochastic reactor model is capable of accurate simulation of combustion under diesel conditions and can also be used to simulate and test different fuels. p-17_pasternak.pdf (168.34 KB) More Documents & Publications Ricardo's

  16. Heavy Vehicle Simulator

    SciTech Connect (OSTI)

    2015-03-09

    Idaho National Laboratory Heavy Vehicle Simulator located at the Center for Advanced Energy Studies.

  17. Direct photon production from viscous quark-gluon plasma

    SciTech Connect (OSTI)

    Chaudhuri, A. K.; Sinha, Bikash

    2011-03-15

    We simulate direct photon production in the evolution of viscous quark-gluon plasma medium. Photons from Compton and annihilation processes are considered. The viscous effect on photon production is very strong and reliable simulation is possible only in a limited p{sub T} range. For minimally viscous fluid ({eta}/s=0.08), direct photons can be reliably computed only up to p{sub T}{<=}1.3 GeV. With reduced viscosity ({eta}/s=0.04), the limit increases to p{sub T}{<=}2 GeV.

  18. Directional detector of gamma rays

    DOE Patents [OSTI]

    Cox, Samson A.; Levert, Francis E.

    1979-01-01

    A directional detector of gamma rays comprises a strip of an electrical cuctor of high atomic number backed with a strip of a second electrical conductor of low atomic number. These elements are enclosed within an electrical conductor that establishes an electrical ground, maintains a vacuum enclosure and screens out low-energy gamma rays. The detector exhibits a directional sensitivity marked by an increased output in the favored direction by a factor of ten over the output in the unfavored direction.

  19. DOE Directives | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    DOE Directives DOE Directives Directives are the Department of Energy's primary means to communicate and institutionalize directives and policies and to establish requirements, responsibilities, and procedures for Departmental elements and contractors. DOE O 413.3A - Program and Project Management for the Acquisition of Capital Assets DOE G 413.3-1 - Managing Design and Construction Using Systems Engineering for Use with DOE O 413.3A DOE G 413.3-2 - Quality Assurance Guide for Project Management

  20. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    www.directives.doe.gov Directives are the Department of Energy's primary means of establishing policies, requirements, responsibilities, and procedures for Departmental elements and contractors. New - DOE O 430.1C, Real Property Asset Management https://www.directives.doe.gov/news/0430.1C-new The directive establishes an integrated corporate-level, performance based approach to the life-cycle management of our real property assets. It links real property asset planning, programming, budgeting

  1. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    SciTech Connect (OSTI)

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  2. Quasi-spherical direct drive fusion.

    SciTech Connect (OSTI)

    VanDevender, J. Pace; Abbott, Lucas M.; Langston, William L.; McDaniel, Dillon Heirman; Nash, Thomas J.; Roderick, Norman Frederick; Silva, M.

    2007-01-01

    The authors present designs of quasi-spherical direction drive z-pinch loads for machines such as ZR at 28 MA load current with a 150 ns implosion time (QSDDI). A double shell system for ZR has produced a 2D simulated yield of 12 MJ, but the drive for this system on ZR has essentially no margin. A double shell system for a 56 MA driver at 150 ns implosion has produced a simulated yield of 130 MJ with considerable margin in attaining the necessary temperature and density-radius product for ignition. They also represent designs for a magnetically insulated current amplifier, (MICA), that modify the attainable ZR load current to 36 MA with a 28 ns rise time. The faster pulse provided by a MICA makes it possible to drive quasi-spherical single shell implosions (QSDD2). They present results from 1D LASNEX and 2D MACH2 simulations of promising low-adiabat cryogenic QSDD2 capsules and 1D LASNEX results of high-adiabat cryogenic QSDD2 capsules.

  3. Directives for Review FY 2015 - DOE Directives, Delegations, and

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Requirements FY 2015 by Diane Johnson Excel spreadsheet icon DirectivesUpForReview-EOFY2015.xls - Excel spreadsheet, 64 KB (66048

  4. Directives for Review FY 2015 - DOE Directives, Delegations,...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    FY 2015 by Diane Johnson Excel spreadsheet icon DirectivesUpForReview-EOFY2015.xls - Excel spreadsheet, 64 KB (66048

  5. Crosswalk of Directives Numbering System - DOE Directives, Delegations,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Requirements Crosswalk of Directives Numbering System by Website Administrator PDF document icon CROSWLK-3-27-2014.pdf - PDF document, 132 KB (135996 bytes

  6. Design and Simulation of Hybridization Experiments

    Energy Science and Technology Software Center (OSTI)

    1995-11-28

    DB EXP DESIGN is a suite of three UNIX shell-like programs, DWC which computes oligomer composition of DNA texts using directed acyclic word data structures; DWO, which simulates hybridization experiments; and DMI, which calculates the information contenet of individual probes, their mutual information content, and their joint information content through estimation of Markov trees.

  7. Weld arc simulator

    DOE Patents [OSTI]

    Burr, Melvin J.

    1990-01-30

    An arc voltage simulator for an arc welder permits the welder response to a variation in arc voltage to be standardized. The simulator uses a linear potentiometer connected to the electrode to provide a simulated arc voltage at the electrode that changes as a function of electrode position.

  8. Electrical Circuit Simulation Code

    Energy Science and Technology Software Center (OSTI)

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  9. European Lean Gasoline Direct Injection Vehicle Benchmark

    SciTech Connect (OSTI)

    Chambon, Paul H; Huff, Shean P; Edwards, Kevin Dean; Norman, Kevin M; Prikhodko, Vitaly Y; Thomas, John F

    2011-01-01

    Lean Gasoline Direct Injection (LGDI) combustion is a promising technical path for achieving significant improvements in fuel efficiency while meeting future emissions requirements. Though Stoichiometric Gasoline Direct Injection (SGDI) technology is commercially available in a few vehicles on the American market, LGDI vehicles are not, but can be found in Europe. Oak Ridge National Laboratory (ORNL) obtained a European BMW 1-series fitted with a 2.0l LGDI engine. The vehicle was instrumented and commissioned on a chassis dynamometer. The engine and after-treatment performance and emissions were characterized over US drive cycles (Federal Test Procedure (FTP), the Highway Fuel Economy Test (HFET), and US06 Supplemental Federal Test Procedure (US06)) and steady state mappings. The vehicle micro hybrid features (engine stop-start and intelligent alternator) were benchmarked as well during the course of that study. The data was analyzed to quantify the benefits and drawbacks of the lean gasoline direct injection and micro hybrid technologies from a fuel economy and emissions perspectives with respect to the US market. Additionally that data will be formatted to develop, substantiate, and exercise vehicle simulations with conventional and advanced powertrains.

  10. DOE Directives | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    DOE Directives DOE Directives DOE Directives Initiated by the IG DOE O 221.3A, Establishment of Management Decisions on Office of Inspector General Reports - April 19, 2008 DOE O 221.1A, Reporting Fraud, Waste and Abuse to the Office of Inspector General - April 19, 2008 DOE O 221.2A, Cooperation with the Office of Inspector General - February 25, 2008 DOE O 224.2A, Auditing of Programs and Operations - November 9, 2007

  11. Direct cooled power electronics substrate

    DOE Patents [OSTI]

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W. [Kingston, TN; Lowe, Kirk T. [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  12. Laboratory Directed Research and Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Phone Book Jobs Laboratory Directorate - Strategic Planning Office Laboratory Directed Research and Development (LDRD) LBNL LDRD Program Guidelines LDRD FY 2017 Call for...

  13. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-04-30

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation

  14. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    News Item Packaging and Transportation for Offsite Shipment of Materials of National Security Interest https:www.directives.doe.govinformational-purposes-only...

  15. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation.

  16. Sunlight Direct | Open Energy Information

    Open Energy Info (EERE)

    Sector: Solar Product: Developed a system that tracks and concentrates solar energy for distributed power generation Website: www.sunlight-direct.com Coordinates: 33.0013938,...

  17. Air Shower Simulations

    SciTech Connect (OSTI)

    Alania, Marco; Gomez, Adolfo V. Chamorro; Araya, Ignacio J.; Huerta, Humberto Martinez; Flores, Alejandra Parra; Knapp, Johannes

    2009-04-30

    Air shower simulations are a vital part of the design of air shower experiments and the analysis of their data. We describe the basic features of air showers and explain why numerical simulations are the appropriate approach to model the shower simulation. The CORSIKA program, the standard simulation program in this field, is introduced and its features, performance and limitations are discussed. The basic principles of hadronic interaction models and some gerneral simulation techniques are explained. Also a brief introduction to the installation and use of CORSIKA is given.

  18. Efficient Placement of Directional Antennas

    SciTech Connect (OSTI)

    Pan, Feng; Kasiviswanathan, Shiva

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  19. Reactor refueling machine simulator

    SciTech Connect (OSTI)

    Rohosky, T.L.; Swidwa, K.J.

    1987-10-13

    This patent describes in combination: a nuclear reactor; a refueling machine having a bridge, trolley and hoist each driven by a separate motor having feedback means for generating a feedback signal indicative of movement thereof. The motors are operable to position the refueling machine over the nuclear reactor for refueling the same. The refueling machine also has a removable control console including means for selectively generating separate motor signals for operating the bridge, trolley and hoist motors and for processing the feedback signals to generate an indication of the positions thereof, separate output leads connecting each of the motor signals to the respective refueling machine motor, and separate input leads for connecting each of the feedback means to the console; and a portable simulator unit comprising: a single simulator motor; a single simulator feedback signal generator connected to the simulator motor for generating a simulator feedback signal in response to operation of the simulator motor; means for selectively connecting the output leads of the console to the simulator unit in place of the refueling machine motors, and for connecting the console input leads to the simulator unit in place of the refueling machine motor feedback means; and means for driving the single simulator motor in response to any of the bridge, trolley or hoist motor signals generated by the console and means for applying the simulator feedback signal to the console input lead associated with the motor signal being generated by the control console.

  20. Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry: Spray Simulations

    SciTech Connect (OSTI)

    Rutland, Christopher J.

    2009-04-26

    The Terascale High-Fidelity Simulations of Turbulent Combustion (TSTC) project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of the approach is direct numerical simulation (DNS) featuring the highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. Under this component of the TSTC program the simulation code named S3D, developed and shared with coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for turbulent liquid fuel spray dynamics. Major accomplishments include improved fundamental understanding of mixing and auto-ignition in multi-phase turbulent reactant mixtures and turbulent fuel injection spray jets.

  1. Fast Analysis and Simulation Team | NISAC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NISACFast Analysis and Simulation Team

  2. Browse Draft Directives - DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Browse Draft Directives Current Draft Archives by Website Administrator More filters Less filters Directive Type Order Guide Manual Policy Notice Cancellation Notice HQ Order Sec of Energy Notice Justification Memorandum Certification Memo 0 Series Series All 0000 Subject Classification 100 Leadership/Management Planning 200 Information and Analysis 300 Human Resources 400 Work Processes 500 Business and Support Services 1100 Org. Authorities, Functions and Internal Relationships 1200 External

  3. Parallel Atomistic Simulations

    SciTech Connect (OSTI)

    HEFFELFINGER,GRANT S.

    2000-01-18

    Algorithms developed to enable the use of atomistic molecular simulation methods with parallel computers are reviewed. Methods appropriate for bonded as well as non-bonded (and charged) interactions are included. While strategies for obtaining parallel molecular simulations have been developed for the full variety of atomistic simulation methods, molecular dynamics and Monte Carlo have received the most attention. Three main types of parallel molecular dynamics simulations have been developed, the replicated data decomposition, the spatial decomposition, and the force decomposition. For Monte Carlo simulations, parallel algorithms have been developed which can be divided into two categories, those which require a modified Markov chain and those which do not. Parallel algorithms developed for other simulation methods such as Gibbs ensemble Monte Carlo, grand canonical molecular dynamics, and Monte Carlo methods for protein structure determination are also reviewed and issues such as how to measure parallel efficiency, especially in the case of parallel Monte Carlo algorithms with modified Markov chains are discussed.

  4. UTILITY OF MECHANISTIC MODELS FOR DIRECTING ADVANCED SEPARATIONS RESEARCH & DEVELOPMENT ACTIVITIES: Electrochemically Modulated Separation Example

    SciTech Connect (OSTI)

    Schwantes, Jon M.

    2009-06-01

    The objective for this work was to demonstrate the utility of mechanistic computer models designed to simulate actinide behavior for use in efficiently and effectively directing advanced laboratory R&D activities associated with developing advanced separations methods.

  5. FY 2011 Third Quarter Report Estimate of Historical Aerosol Direct and Indirect Effects

    SciTech Connect (OSTI)

    Koch, D

    2011-06-22

    The global and annual mean aerosol direct and indirect effects estimated from Community Earth System Model (CESM) simulations are -0.06 W m-2 and -1.39 W m-2, respectively.

  6. Device Simulation Tool - JCAP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PAZ0036_v2.jpg Device Simulation Tool Research Why Solar Fuels Goals & Objectives Thrust 1 Thrust 2 Thrust 3 Thrust 4 Publications Research Highlights Videos Innovations User Facilities Expert Team Benchmarking Database Device Simulation Tool XPS Spectral Database Research Introduction Why Solar Fuels? Goals & Objectives Thrusts Thrust 1 Thrust 2 Thrust 3 Thrust 4 Library Publications Research Highlights Videos Resources User Facilities Expert Team Benchmarking Database Device Simulation

  7. Modeling & Simulation publications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling and Simulation in the Chemical Sciences » Modeling & Simulation Publications Modeling & Simulation publications Research into alternative forms of energy, especially energy security, is one of the major national security imperatives of this century. Get Expertise David Harradine Physical Chemistry and Applied Spectroscopy Email Josh Smith Chemistry Email The inherent knowledge of transformation has beguiled sorcerers and scientists alike. D.A. Horner, F. Lambert, J.D. Kress,

  8. Module bay with directed flow

    DOE Patents [OSTI]

    Torczynski, John R.

    2001-02-27

    A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.

  9. Directional fast-neutron detector

    DOE Patents [OSTI]

    Byrd, Roger C. (Albuquerque, NM)

    1994-01-01

    A plurality of omnidirectional radiation detectors are arranged in a close packed symmetrical pattern to form a segmented detector. The output radiation counts from these detectors are arithmetically combined to provide the direction of a source of incident radiation. Directionality is achieved without the use of shielding to provide collimation and background reduction effects. Indeed, output counts from paired detectors are simply subtracted to yield a vector direction toward the radiation source. The counts from all of the detectors can be combined to yield an output signal functionally related to the radiation source strength.

  10. Whole Building Energy Simulation

    Broader source: Energy.gov [DOE]

    Whole building energy simulation, also referred to as energy modeling, can and should be incorporated early during project planning to provide energy impact feedback for which design considerations...

  11. Nonimaging radiant energy direction device

    DOE Patents [OSTI]

    Winston, Roland

    1980-01-01

    A raidant energy nonimaging light direction device is provided. The device includes an energy transducer and a reflective wall whose contour is particularly determined with respect to the geometrical vector flux of a field associated with the transducer.

  12. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2001-01-08

    To establish the Department's, including the NNSA's, requirements for laboratory-directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Cancels DOE O 413.2. Canceled by DOE O 413.2B.

  13. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-04-19

    The Order establishes DOE requirements and responsibilities for laboratory directed research and development while providing laboratory directors with broad flexibility for program implementation. Cancels DOE O 413.2A. Admin Chg 1, 1-31-11.

  14. DRIFT COMPENSATED DIRECT COUPLED AMPLIFIER

    DOE Patents [OSTI]

    Windsor, A.A.

    1959-05-01

    An improved direct-coupled amplifier having zerolevel drift correction is described. The need for an auxiliary corrective-potential amplifier is eliminated thereby giving protection against overload saturation of the zero- level drift correcting circuit. (T.R.H.)

  15. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2015-10-22

    To establish Department of Energy (DOE) requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Supersedes DOE O 413.2B.

  16. DOE Directives | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Directives DOE Directives DOE O 414.1D, Quality Assurance DOE G 414.1-2B Admin Change 1, Quality Assurance Program Guide DOE O 221.1A, Reporting Fraud, Waste and Abuse to the Office of the Inspector General DOE O 232.2, Occurrence Reporting and Processing of Operations Information DOE O 440.1B, Worker Protection Program for DOE (Including the NNSA) Federal Employees

  17. DOE Directives, Delegations, and Requirements

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Contact form Directives are the Department of Energy's primary means of establishing policies, requirements, responsibilities, and procedures for Departmental elements and contractors. Directives Program Management Emily Stanton, (202) 287-5641 Rachel Mack, (202) 287-6804 Delegation Program Management Gail Cephas,(202) 586-1049 Web Site Administration Technical Support Staff, (505) 663-1302 Fill in this form to contact us. Name Please enter your full name E-Mail (Required) Please enter your

  18. Modeling direct interband tunneling. II. Lower-dimensional structures

    SciTech Connect (OSTI)

    Pan, Andrew; Chui, Chi On

    2014-08-07

    We investigate the applicability of the two-band Hamiltonian and the widely used Kane analytical formula to interband tunneling along unconfined directions in nanostructures. Through comparisons with kp and tight-binding calculations and quantum transport simulations, we find that the primary correction is the change in effective band gap. For both constant fields and realistic tunnel field-effect transistors, dimensionally consistent band gap scaling of the Kane formula allows analytical and numerical device simulations to approximate non-equilibrium Green's function current characteristics without arbitrary fitting. This allows efficient first-order calibration of semiclassical models for interband tunneling in nanodevices.

  19. Bioenergy Technologies Office New Directions | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    New Directions Bioenergy Technologies Office New Directions New Directions and New Business Opportunities for BETO Valerie Reed, Acting Director, BETO, U.S. Department of Energy ...

  20. Directed liquid phase assembly of highly ordered metallic nanoparticle arrays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Yueying; Dong, Nanyi; Fu, Shaofang; Fowlkes, Jason D.; Kondic, Lou; Vincenti, Maria A.; de Ceglia, Domenico; Rack, Philip D.

    2014-04-01

    Directed assembly of nanomaterials is a promising route for the synthesis of advanced materials and devices. We demonstrate the directed-assembly of highly ordered two-dimensional arrays of hierarchical nanostructures with tunable size, spacing and composition. The directed assembly is achieved on lithographically patterned metal films that are subsequently pulse-laser melted; during the brief liquid lifetime, the pattened nanostructures assemble into highly ordered primary and secondary nanoparticles, with sizes below that which was originally patterned. Complementary fluid-dynamics simulations emulate the resultant patterns and show how the competition of capillary forces and liquid metal–solid substrate interaction potential drives the directed assembly. Lastly, asmore » an example of the enhanced functionality, a full-wave electromagnetic analysis has been performed to identify the nature of the supported plasmonic resonances.« less

  1. Directed liquid phase assembly of highly ordered metallic nanoparticle arrays

    SciTech Connect (OSTI)

    Wu, Yueying; Dong, Nanyi; Fu, Shaofang; Fowlkes, Jason D.; Kondic, Lou; Vincenti, Maria A.; de Ceglia, Domenico; Rack, Philip D.

    2014-04-01

    Directed assembly of nanomaterials is a promising route for the synthesis of advanced materials and devices. We demonstrate the directed-assembly of highly ordered two-dimensional arrays of hierarchical nanostructures with tunable size, spacing and composition. The directed assembly is achieved on lithographically patterned metal films that are subsequently pulse-laser melted; during the brief liquid lifetime, the pattened nanostructures assemble into highly ordered primary and secondary nanoparticles, with sizes below that which was originally patterned. Complementary fluid-dynamics simulations emulate the resultant patterns and show how the competition of capillary forces and liquid metal–solid substrate interaction potential drives the directed assembly. Lastly, as an example of the enhanced functionality, a full-wave electromagnetic analysis has been performed to identify the nature of the supported plasmonic resonances.

  2. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, Michael A.; Crowell, John M.

    1987-01-01

    A small battery operated nuclear spectrum simulator having a noise source nerates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith generates several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  3. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, M.A.; Crowell, J.M.

    1985-04-09

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  4. Radio Channel Simulator (RCSM)

    Energy Science and Technology Software Center (OSTI)

    2007-01-31

    This is a simulation package for making site specific predictions of radio signal strength. The software computes received power at discrete grid points as a function of the transmitter location and propagation environment. It is intended for use with wireless network simulation packages and to support wireless network deployments.

  5. Damselfly Network Simulator

    Energy Science and Technology Software Center (OSTI)

    2014-04-01

    Damselfly is a model-based parallel network simulator. It can simulate communication patterns of High Performance Computing applications on different network topologies. It outputs steady-state network traffic for a communication pattern, which can help in studying network congestion and its impact on performance.

  6. Converting DYNAMO simulations to Powersim Studio simulations

    SciTech Connect (OSTI)

    Walker, La Tonya Nicole; Malczynski, Leonard A.

    2014-02-01

    DYNAMO is a computer program for building and running 'continuous' simulation models. It was developed by the Industrial Dynamics Group at the Massachusetts Institute of Technology for simulating dynamic feedback models of business, economic, and social systems. The history of the system dynamics method since 1957 includes many classic models built in DYANMO. It was not until the late 1980s that software was built to take advantage of the rise of personal computers and graphical user interfaces that DYNAMO was supplanted. There is much learning and insight to be gained from examining the DYANMO models and their accompanying research papers. We believe that it is a worthwhile exercise to convert DYNAMO models to more recent software packages. We have made an attempt to make it easier to turn these models into a more current system dynamics software language, Powersim Studio produced by Powersim AS2 of Bergen, Norway. This guide shows how to convert DYNAMO syntax into Studio syntax.

  7. Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vehicle Technologies Office Merit Review 2014: Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine Development Advanced Gasoline Turbocharged Direct Injection (GTDI) ...

  8. Advanced Particulate Filter Technologies for Direct Injection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Particulate Filter Technologies for Direct Injection Gasoline Engine Applications Advanced Particulate Filter Technologies for Direct Injection Gasoline Engine Applications Specific ...

  9. Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Turbocharged Direct Injection (GTDI) Engine Development Vehicle Technologies Office Merit Review 2014: Advanced Gasoline Turbocharged Direct Injection (GTDI) Engine ...

  10. Optically Directed Assembly of Continuous Mesoscale Filaments...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Accepted Manuscript: Optically Directed Assembly of Continuous Mesoscale Filaments Title: Optically Directed Assembly of Continuous Mesoscale Filaments Authors: Bahns, ...

  11. The AISI direct steelmaking program

    SciTech Connect (OSTI)

    Aukrust, E. ); Downing, K.B. )

    1991-01-01

    After six months of operation of the pilot plant, the viability of in-bath smelting combined with a high level of post combustion has been demonstrated, and the opportunity exists for an early commercialization of the direct ironmaking part of the process while we continue to research direct steelmaking. The program should be of equal interest to integrated and electric furnace producers. Smelting of ore provides virgin iron units. Additionally, the process has the flexibility of melting scrap and varying the ore-to-scrap ratio over wide ranges. This process does not require coke, thus eliminating the cokemaking operation, a major source of environmental concern.

  12. Enabling Green Energy and Propulsion Systems via Direct Noise Computation |

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Argonne Leadership Computing Facility High-fidelity simulation of exhaust nozzle under installed configuration Umesh Paliath, GE Global Research; Joe Insley, Argonne National Laboratory Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI Email: paliath@ge.com Institution: GE Global Research Allocation Program: INCITE Allocation Hours at ALCF: 105 Million Year: 2013 Research Domain: Engineering GE Global Research is using the Argonne Leadership

  13. Global Feedback Simulator

    SciTech Connect (OSTI)

    Carlos Serrano, Lawrence Doolittle

    2015-10-29

    GFS is a simulation engine that is used for the characterization of Accelerator performance parameters based on the machine layout, configuration and noise sources. It combines extensively tested Feedback models with a longitudinal phase space tracking simulator along with the interaction between the two via beam-based feedback using a computationally efficient simulation engine. The models include beam instrumentation, considerations on loop delays for in both the R and beam-based feedback loops, as well as the ability to inject noise (both correlated and uncorrelated) at different points of the machine including a full characterization of the electron gun performance parameters.

  14. Global Feedback Simulator

    Energy Science and Technology Software Center (OSTI)

    2015-10-29

    GFS is a simulation engine that is used for the characterization of Accelerator performance parameters based on the machine layout, configuration and noise sources. It combines extensively tested Feedback models with a longitudinal phase space tracking simulator along with the interaction between the two via beam-based feedback using a computationally efficient simulation engine. The models include beam instrumentation, considerations on loop delays for in both the R and beam-based feedback loops, as well as themore » ability to inject noise (both correlated and uncorrelated) at different points of the machine including a full characterization of the electron gun performance parameters.« less

  15. Regional Transportation Simulation Tool for Emergency Planning

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    rtstep-diag TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Regional Transportation Simulation Tool for Emergency Evacuation Planning (Click to play movie) Large-scale evacuations from major cities during no-notice events - such as chemical or radiological attacks, hazardous material spills, or earthquakes - have an obvious impact on large regions rather than on just the directly affected area. The scope of impact includes the

  16. Numerical simulations of strong incompressible magnetohydrodynamic turbulence

    SciTech Connect (OSTI)

    Mason, J.; Cattaneo, F.; Perez, J. C.; Boldyrev, S.

    2012-05-15

    Magnetised plasma turbulence pervades the universe and is likely to play an important role in a variety of astrophysical settings. Magnetohydrodynamics (MHD) provides the simplest theoretical framework in which phenomenological models for the turbulent dynamics can be built. Numerical simulations of MHD turbulence are widely used to guide and test the theoretical predictions; however, simulating MHD turbulence and accurately measuring its scaling properties is far from straightforward. Computational power limits the calculations to moderate Reynolds numbers and often simplifying assumptions are made in order that a wider range of scales can be accessed. After describing the theoretical predictions and the numerical approaches that are often employed in studying strong incompressible MHD turbulence, we present the findings of a series of high-resolution direct numerical simulations. We discuss the effects that insufficiencies in the computational approach can have on the solution and its physical interpretation.

  17. Dynamic procedure for filtered gyrokinetic simulations

    SciTech Connect (OSTI)

    Morel, P.; Banon Navarro, A.; Albrecht-Marc, M.; Carati, D.; Merz, F.; Goerler, T.; Jenko, F.

    2012-01-15

    Large eddy simulations (LES) of gyrokinetic plasma turbulence are investigated as interesting candidates to decrease the computational cost. A dynamic procedure is implemented in the gene code, allowing for dynamic optimization of the free parameters of the LES models (setting the amplitudes of dissipative terms). Employing such LES methods, one recovers the free energy and heat flux spectra obtained from highly resolved direct numerical simulations. Systematic comparisons are performed for different values of the temperature gradient and magnetic shear, parameters which are of prime importance in ion temperature gradient driven turbulence. Moreover, the degree of anisotropy of the problem, which can vary with parameters, can be adapted dynamically by the method that shows gyrokinetic large eddy simulation to be a serious candidate to reduce numerical cost of gyrokinetic solvers.

  18. Laboratory Directed Research and Development

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2006-04-19

    The order establishes DOE requirements for laboratory directed research and development (LDRD) while providing the laboratory director broad flexibility for program implementation. Cancels DOE O 413.3A. Admin Chg 1, dated 1-31-11, cancels DOE O 413.2B. Certified 7-14-2011.

  19. Direct flow crystal growth system

    DOE Patents [OSTI]

    Montgomery, Kenneth E.; Milanovich, Fred P.

    1992-01-01

    A crystal is grown in a constantly filtered solution which is flowed directly into the growing face of a crystal. In a continuous flow system, solution at its saturation temperature is removed from a crystal growth tank, heated above its saturation temperature, filtered, cooled back to its saturation temperature, and returned to the tank.

  20. Fundamentals of plasma simulation

    SciTech Connect (OSTI)

    Forslund, D.W.

    1985-01-01

    With the increasing size and speed of modern computers, the incredibly complex nonlinear properties of plasmas in the laboratory and in space are being successfully explored in increasing depth. Of particular importance have been numerical simulation techniques involving finite size particles on a discrete mesh. After discussing the importance of this means of understanding a variety of nonlinear plasma phenomena, we describe the basic elements of particle-in-cell simulation and their limitations and advantages. The differencing techniques, stability and accuracy issues, data management and optimization issues are discussed by means of a simple example of a particle-in-cell code. Recent advances in simulation methods allowing large space and time scales to be treated with minimal sacrifice in physics are reviewed. Various examples of nonlinear processes successfully studied by plasma simulation will be given.

  1. Compressible Astrophysics Simulation Code

    Energy Science and Technology Software Center (OSTI)

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  2. Dynamic Power Grid Simulation

    Energy Science and Technology Software Center (OSTI)

    2015-09-14

    GridDyn is a part of power grid simulation toolkit. The code is designed using modern object oriented C++ methods utilizing C++11 and recent Boost libraries to ensure compatibility with multiple operating systems and environments.

  3. Xyce parallel electronic simulator.

    SciTech Connect (OSTI)

    Keiter, Eric Richard; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd Stirling; Pawlowski, Roger Patrick; Santarelli, Keith R.

    2010-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.

  4. Modeling & Simulation | NISAC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NISACModeling & Simulation content top Overview Posted by Admin on Feb 13, 2012 in | Comments 0 comments NISAC experts analyze-using modeling and simulation capabilities-critical infrastructure, along with their interdependencies, vulnerabilities, and complexities. Their analyses are used to aid decisionmakers with policy assessment, mitigation planning, education, and training and provide near-real-time assistance to crisis-response organizations. Infrastructure systems are large, complex,

  5. Advanced Simulation and Computing

    National Nuclear Security Administration (NNSA)

    NA-ASC-117R-09-Vol.1-Rev.0 Advanced Simulation and Computing PROGRAM PLAN FY09 October 2008 ASC Focal Point Robert Meisner, Director DOE/NNSA NA-121.2 202-586-0908 Program Plan Focal Point for NA-121.2 Njema Frazier DOE/NNSA NA-121.2 202-586-5789 A Publication of the Office of Advanced Simulation & Computing, NNSA Defense Programs i Contents Executive Summary ----------------------------------------------------------------------------------------------- 1 I. Introduction

  6. Theory Modeling and Simulation

    SciTech Connect (OSTI)

    Shlachter, Jack

    2012-08-23

    Los Alamos has a long history in theory, modeling and simulation. We focus on multidisciplinary teams that tackle complex problems. Theory, modeling and simulation are tools to solve problems just like an NMR spectrometer, a gas chromatograph or an electron microscope. Problems should be used to define the theoretical tools needed and not the other way around. Best results occur when theory and experiments are working together in a team.

  7. Dynamic extension of the Simulation Problem Analysis Kernel (SPANK)

    SciTech Connect (OSTI)

    Sowell, E.F. . Dept. of Computer Science); Buhl, W.F. )

    1988-07-15

    The Simulation Problem Analysis Kernel (SPANK) is an object-oriented simulation environment for general simulation purposes. Among its unique features is use of the directed graph as the primary data structure, rather than the matrix. This allows straightforward use of graph algorithms for matching variables and equations, and reducing the problem graph for efficient numerical solution. The original prototype implementation demonstrated the principles for systems of algebraic equations, allowing simulation of steady-state, nonlinear systems (Sowell 1986). This paper describes how the same principles can be extended to include dynamic objects, allowing simulation of general dynamic systems. The theory is developed and an implementation is described. An example is taken from the field of building energy system simulation. 2 refs., 9 figs.

  8. Analysis of the theoretical bias in dark matter direct detection

    SciTech Connect (OSTI)

    Catena, Riccardo

    2014-09-01

    Fitting the model ''A'' to dark matter direct detection data, when the model that underlies the data is ''B'', introduces a theoretical bias in the fit. We perform a quantitative study of the theoretical bias in dark matter direct detection, with a focus on assumptions regarding the dark matter interactions, and velocity distribution. We address this problem within the effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. We analyze 24 benchmark points in the parameter space of the theory, using frequentist and Bayesian statistical methods. First, we simulate the data of future direct detection experiments assuming a momentum/velocity dependent dark matter-nucleon interaction, and an anisotropic dark matter velocity distribution. Then, we fit a constant scattering cross section, and an isotropic Maxwell-Boltzmann velocity distribution to the simulated data, thereby introducing a bias in the analysis. The best fit values of the dark matter particle mass differ from their benchmark values up to 2 standard deviations. The best fit values of the dark matter-nucleon coupling constant differ from their benchmark values up to several standard deviations. We conclude that common assumptions in dark matter direct detection are a source of potentially significant bias.

  9. Ultra-wideband directional sampler

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-05-14

    The Ultra-Wideband (UWB) Directional Sampler is a four port device that combines the function of a directional coupler with a high speed sampler. Two of the four ports operate at a high sub-nanosecond speed, in ``real time``, and the other two ports operate at a slow millisecond-speed, in ``equivalent time``. A signal flowing inbound to either of the high speed ports is sampled and coupled, in equivalent time, to the adjacent equivalent time port while being isolated from the opposite equivalent time port. A primary application is for a time domain reflectometry (TDR) situation where the reflected pulse returns while the outbound pulse is still being transmitted, such as when the reflecting discontinuity is very close to the TDR apparatus. 3 figs.

  10. Ultra-wideband directional sampler

    DOE Patents [OSTI]

    McEwan, Thomas E.

    1996-01-01

    The Ultra-Wideband (UWB) Directional Sampler is a four port device that combines the function of a directional coupler with a high speed sampler. Two of the four ports operate at a high sub-nanosecond speed, in "real time", and the other two ports operate at a slow millisecond-speed, in "equivalent time". A signal flowing inbound to either of the high speed ports is sampled and coupled, in equivalent time, to the adjacent equivalent time port while being isolated from the opposite equivalent time port. A primary application is for a time domain reflectometry (TDR) situation where the reflected pulse returns while the outbound pulse is still being transmitted, such as when the reflecting discontinuity is very close to the TDR apparatus.